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This glossary of engineering terms is a list of definitions about the major concepts of engineering. Please see the bottom of the page for glossaries of specific fields of engineering.
A
 Absolute electrode potential
 .
 Absolute motion
 .
 Absolute pressure
 Pressure measured in reference to a vacuum
 Absolute zero
 The coldest possible temperature, at which all molecular vibration stops; −273.15° Celsius, or −459.67° Fahrenheit.
 Absorbance
 .
 AC power
 Electric power delivered by alternating current; common household power is AC. .
 Acceleration
 The rate at which the velocity of a body changes with time, and the direction in which that change is acting.
 Acid
 .
 Acidbase reaction
 .
 Acid strength
 In strong acids, most of the molecules give up a hydrogen ion and become ionized.
 Acoustics
 The scientific study of sound.
 Activated sludge
 .
 Activated sludge model
 .
 Active transport
 Transportation of people by walking, cycling, or other human=powered methods.
 Actuator
 The final element of a control loop, that translates control signals into a physical output movement.
 Adenosine triphosphate
 .
 Adhesion
 .
 Adiabatic process
 A process where no heat energy is lost to outside space.
 Adiabatic wall
 A barrier through which heat energy cannot pass.
 Aerobic digestion
 .
 Aerodynamics
 .
 Aerospace engineering
 .
 Afocal system
 .
 Agricultural engineering
 The profession of designing machinery, processes and systems for use in agriculture.
 Albedo
 .
 Algae
 .
 Algebra
 .
 Algorithm
 .
 Alkane
 .
 Alkene
 .
 Alkyne
 .
 Alloy
 .
 Alpha particle
 .
 Alternating current
 Electrical current that regularly reverses direction.
 Alternative hypothesis
 .
 Ammeter
 An instrument that measures current.
 Amino acid
 .
 Amorphous solid
 .
 Ampere
 The SI unit of current flow, one coulomb per second.
 Amphoterism
 .
 Amplifier
 .
 Amplitude
 .
 Anaerobic digestion
 .
 Angular acceleration
 .
 Angular momentum
 .
 Angular velocity
 .
 Anion
 .
 Annealing (metallurgy)
 .
 Annihilation
 .
 Anode
 .
 ANSI
 American National Standards Institute.
 Antigravity
 .
 Antimatter
 .
 Antineutron
 .
 Antiparticle
 .
 Antiproton
 .
 Applied engineering
 .
 Applied mathematics
 .
 Arc length
 .
 Archimedes' principle
 .
 Area moment of inertia
 .
 Arithmetic mean
 .
 Arithmetic sequence
 .
 Aromatic hydrocarbon
 .
 Arrhenius equation
 .
 Artificial intelligence
 The intelligence of machines and the branch of computer science that aims to create it..
 Assembly language
 .
 Atomic packing factor
 The percentage of the volume filled with atomic mass in a crystal formation.
 Atomic physics
 .
 Atomic structure
 .
 Audio frequency
 .
 Austenitization
 .
 Automation
 .
 Automaton
 An early selfoperating robot, performing exactly the same actions, over and over..
 Autonomous vehicle
 A vehicle capable of driving from one point to another without input from a human operator.
 Azimuthal quantum number
 .
B
 Barometer
 A device for measuring pressure.
 Baryon
 .
 Battery
 Electrochemical cells that transform chemical energy into electricity..
 Base
 .
 Baud
 Rate at which data is transferred in symbols/second; a symbol may represent one or more bits.
 Beam
 A structural element whose length is significantly greater than its width or height.
 Beer–Lambert law
 .
 Belt
 .
 Belt friction
 .
 Bending
 .
 Benefit–cost analysis
 .
 Bending moment
 The product of bending force and distance, measured in units of length * distance..
 Bernoulli differential equation
 .
 Bernoulli's equation
 An equation for relating several measurements within a fluid flow, such as velocity, pressure, and potential energy.
 Bernoulli's principle
 .
 Beta particle
 .
 Binomial random variable
 .
 Biocatalysis
 .
 Biomedical engineering
 .
 Biomimetic
 .
 Bionics
 The application of biological methods to engineering systems.
 Biophysics
 .
 Biot number
 .
 Block and tackle
 A system of pulleys and a rope threaded between them, used to lift or pull heavy loads.
 Body force
 .
 Boiler
 A device whose purpose is to add heat to a working fluid in order to vaporize it..
 Boiler (power generation)
 .
 Boiling point
 The state at which a substance becomes gaseous..
 Boilingpoint elevation
 .
 Boltzmann constant
 .
 Boson
 .
 Boyle's law
 .
 Bravais lattice
 .
 Brayton cycle
 .
 Breakeven analysis
 .
 Brewster's angle
 .
 Brittle
 .
 Bromide
 Any chemical substance made up of Bromine, along with other elements.
 Brønsted–Lowry acid–base theory
 .
 Brownian motion
 .
 Buckingham π theorem
 A method for determining ∏ groups, or dimensionless descriptors of physical phenomena.
 Buffer solution
 .
 Bulk modulus
 .
 Buoyancy
 A force caused by displacement in a fluid by an object of different density than the fluid.

C
 Calculus
 The mathematics of change.
 Capacitance
 The ability of a body to store electrical charge.
 Capacitive reactance
 The impedance of a capacitor in an alternating current circuit, the opposition to current flow.
 Capacitor
 .
 Capillarity
 .
 Carbonate
 .
 Carnot cycle
 A hypothetical thermodynamic cycle for a heat engine; no thermodynamic cycle can be more efficient than a Carnot cycle operating between the same two temperature limits.
 Cartesian coordinates
 Coordinates within a rectangular Cartesian plane.
 Castigliano's method
 .
 Casting
 .
 Cathode
 .
 Cathode ray
 The stream of electrons emitted from a heated negative electrode and attracted to a positive electrode.
 Cell membrane
 .
 Cell nucleus
 .
 Cell theory
 .
 Center of gravity
 The center of mas of an object, its balance point.
 Center of mass
 The weighted center of an object; a force applied through the center of mass will not cause rotation of the object.
 Center of pressure
 .
 Central force motion
 .
 Central limit theorem
 .
 Central processing unit
 .
 Centripetal acceleration
 .
 Centripetal force
 A force acting against rotational acceleration.
 Centroid
 The average point of volume for an object.
 Centrosome
 .
 Chain reaction
 .
 Change of base rule
 .
 Charles's law
 .
 Chemical bond
 .
 Chemical compound
 .
 Chemical equilibrium
 .
 Chemical kinetics
 .
 Chemical reaction
 .
 Chemistry
 .
 Chloride
 Any chemical compound containing the element chlorine.
 Chloroplast
 .
 Chromate
 .
 Chromosome
 .
 Circle
 .
 Circular motion
 .
 Civil engineering
 .
 Clausius–Clapeyron relation
 .
 Clausius inequality
 .
 Clausius theorem
 .
 Coefficient of performance
 .
 Coefficient of variation
 .
 Coherence
 .
 Cohesion
 .
 Combustion
 .
 Compensation
 .
 Compiler
 A computer program that translates a highlevel language into machine language.
 Compressive strength
 .
 Computational fluid dynamics
 .
 Computer
 .
 Computeraided design
 .
 Computeraided engineering
 .
 Computeraided manufacturing
 .
 Computer engineering
 .
 Computer science
 .
 Concave lens
 .
 Condensed matter physics
 .
 Confidence interval
 .
 Conjugate acid
 .
 Conjugate base
 .
 Continuum mechanics
 .
 Control systems engineering
 .
 Convex lens
 .
 Corrosion
 .
 Cosmic rays
 .
 Coulomb
 .
 Coulomb's law
 .
 Covalent bond
 .
 Crookes tube
 A type of vacuum tube that demonstrates cathode rays.
 Cryogenics
 The science of low temperatures.
 Crystallization
 .
 Crystallography
 The study of crystals.
 Curvilinear motion
 .
 Cyclotron
 A subatomic particle accelerator using fixed magnets to direct particles into a spiral path.
D
 Dalton's law
 .
 Damped vibration
 Any vibration with a force acting against it in order to lessen the vibration over time.
 Darcy–Weisbach equation
 An equation used in fluid mechanics to find the pressure change cause by friction within a pipe or conduit.
 DC motor
 An electrical motor driven by direct current.
 Decibel
 A logarithmic unit of ratios.
 Definite integral
 .
 Deflection
 .
 Deformation (engineering)
 .
 Deformation (mechanics)
 .
 Degrees of freedom
 The number of parameters required to define the motion of a dynamical system.
 Delta robot
 A tripod linkage, used to construct fastacting manipulators with a wide range of movement.
 Deltawye transformer
 .
 De Moivre–Laplace theorem
 .
 Density
 The amount of mass in a given unit of volume.
 Derivative
 .
 Design engineering
 .
 Dew point
 The pressure and temperature at which air is holding the maximum possible humidity.
 Dielectric
 .
 Differential pulley
 .
 Differential signaling
 .
 Diffusion
 .
 Dimensional analysis
 .
 Direct integration of a beam
 .
 Dispersion
 .
 Displacement (fluid)
 .
 Displacement (vector)
 .
 Distance
 .
 Doppler effect
 .
 Drag
 .
 Ductility
 .
 Dynamics
 .
 Dyne
 The CGS unit of force.
E
 Economics
 The scientific study of the production, distribution and consumption of goods.
 Elastic modulus
 The amount a material will deform per unit force.
 Elasticity
 .
 Electric charge
 .
 Electric circuit
 .
 Electric current
 .
 Electric displacement field
 .
 Electric generator
 .
 Electric field
 .
 Electric field gradient
 .
 Electric motor
 .
 Electric potential
 .
 Electrical potential energy
 .
 Electric power
 .
 Electrical and electronics engineering
 .
 Electrical conductance
 .
 Electrical conductor
 .
 Electrical impedance
 .
 Electrical insulator
 .
 Electrical network
 .
 Electrical resistance
 .
 Electricity
 .
 Electrodynamics
 .
 Electromagnet
 .
 Electromagnetic field
 .
 Electromagnetic radiation
 .
 Electromechanics
 .
 Electron
 .
 Electronvolt
 .
 Electron pair
 .
 Electronegativity
 .
 Electronics
 .
 Endothermic
 A reaction which requires the absorption of heat.
 Energy
 .
 Engine
 .
 Engineering
 .
 Engineering economics
 .
 Engineering ethics
 .
 Environmental engineering
 .
 Engineering physics
 .
 Enzyme
 .
 Escape velocity
 The minimum velocity at which an object can escape a gravitation field..
 Estimator
 .
 EulerBernoulli beam equation
 .
 Exothermic
 A reaction which produces heat.
F
 Factor of safety
 .
 Falling bodies
 .
 Farad
 The SI unit of capacitance.
 Faraday
 .
 Faraday constant
 .
 Fermat's principle
 .
 Fick's laws of diffusion
 .
 Finite element method
 .
 FIRST
 For Inspiration and Recognition of Science and Technology – is an organization founded by inventor Dean Kamen in 1989 in order to develop ways to inspire students in engineering and technology fields.
 Fission
 .
 Fixed capacitor
 .
 Fixed inductor
 .
 Fixed resistor
 .
 Flow velocity
 .
 Fluid
 .
 Fluid dynamics
 .
 Fluid mechanics
 .
 Fluid physics
 .
 Fluid statics
 .
 Flywheel
 .
 Focus
 .
 In the systems that use feet, the unit of work.
 Fracture toughness
 .
 Fraunhofer lines
 .
 Free fall
 .
 Frequency modulation
 .
 Freezing point
 .
 Friction
 .
 Function
 .
 Fundamental frequency
 .
 Fundamental interaction
 .
 Fundamental theorem of calculus
 .
 Fundamentals of Engineering Examination
 .
 Fusion
 .
G
 Galvanic cell
 .
 Gamma rays
 .
 Gas
 .
 Geiger counter
 A device that measures radioactivity.
 General relativity
 .
 Geometric mean
 .
 Geometry
 .
 Geophysics
 .
 Geotechnical engineering
 .
 Gluon
 .
 Graham's law of diffusion
 .
 Gravitation
 .
 Gravitational constant
 .
 Gravitational energy
 .
 Gravitational field
 .
 Gravitational potential
 .
 Gravitational wave
 .
 Gravity
 .
 Ground state
 .

H
 Halflife
 The period at which onehalf of a quantity of an unstable isotope has decayed into other elements; the time at which half of a substance has diffused out of or otherwise reacted in a system.
 Haptic
 Tactile feedback technology using the operator's sense of touch. Also sometimes applied to robot manipulators with their own touch sensitivity.
 Hardness
 .
 Harmonic mean
 .
 Heat
 The energy of molecular vibration.
 Heat transfer
 .
 Helmholtz free energy
 .
 Henderson–Hasselbalch equation
 .
 Henry's law
 .
 Hertz
 The SI unit of frequency, one cycle per second.
 Hexapod
 (platform) – a movable platform using six linear actuators. Often used in flight simulators they also have applications as a robotic manipulator.
 Hexapod
 (walker) – a sixlegged walking robot, using a simple insectlike locomotion.
 Hoist
 .
 Horsepower
 In measurement systems that use feet, the unit of power.
 Huygens–Fresnel principle
 .
 Hydraulics
 The study of fluid flow, or the generation of mechanical force and movement by liquid under pressure.
 Hydrocarbon
 A compound containing hydrogen and carbon atoms only; petroleum is made of hydrocarbons.

I
 Ice point
 .
 Ideal gas
 A model for gases that ignores intermolecular forces. Most gases are approximately ideal at some high temperature and low pressure.
 Ideal gas constant
 The constant in the gas law that relates pressure, volume and temperature.
 Ideal gas law
 An equation defining behavior of an ideal gas.
 Indefinite integral
 .
 Identity
 .
 Impedance (electrical)
 .
 Inertia
 .
 Infrasound
 .
 Integral
 .
 Integral transform
 .
 International System of Units
 .
 Interval estimation
 .
 Ion
 .
 Ionic bond
 .
 Ionization
 .
 Impedance
 The measure of the opposition that a circuit presents to the passage of a current when a voltage is applied.
 Inclined plane
 .
 Inductance
 .
 Inductor
 .
 Industrial engineering
 .
 Inorganic chemistry
 .
 Isotope
 .

J
 Joule
 The SI unit of energy.
 Joule heating
 .
K
 Kalman filter
 A mathematical technique to estimate the value of a sensor measurement, from a series of intermittent and noisy values.
 Kelvin
 The SI scale for temperature relative to absolute zero.
 Kelvin–Planck statement
 .
 Kinematics
 .
L
 Laminar flow
 .
 Laplace transform
 .
 LC circuit
 A circuit consisting entirely of inductors (L) and capacitors (C).
 Le Chatelier's principle
 .
 Lenz's law
 .
 Lepton
 .
 Lever
 .
 L'Hôpital's rule
 .
 Light
 .
 Linear actuator
 A form of motor that generates a linear movement directly.
 Linear algebra
 The mathematics of equations where the unknowns are only in the first power.
 Linear elasticity
 .
 Liquid
 .
 Logarithm
 .
 Logarithmic identities
 .
 Logarithmic mean temperature difference
 .
 Lumped capacitance model
 .
 Lumped element model
 .
M
 Macaulay's method
 .
 Mach number
 The ratio of the speed of an object to the speed of sound..
 Machine
 .
 Machine code
 .
 Machine element
 .
 Machine learning
 .
 Maclaurin series
 .
 Magnetic field
 .
 Magnetism
 .
 Manufacturing engineering
 .
 Mass balance
 .
 Mass density
 .
 Mass moment of inertia
 .
 Mass number
 .
 Mass spectrometry
 .
 Material failure theory
 .
 Material properties
 .
 Materials science
 .
 Mathematical optimization
 .
 Mathematical physics
 .
 Mathematics
 .
 Matrix
 .
 Matter
 .
 Maximumdistortion energy theory
 .
 Maximumnormalstress theory
 .
 Maximum shear stress
 .
 Maxwell's equations
 A number of basic laws describing the behavior of electric current and potential.
 Mean
 .
 Measures of central tendency
 .
 Mechanical advantage
 .
 Mechanical engineering
 .
 Mechanical filter
 .
 Mechanical wave
 .
 Mechanics
 .
 Mechanism
 .
 Median
 .
 Melting
 .
 Melting point
 .
 Meson
 .
 Metal alloy
 .
 Metallic bond
 .
 Midrange
 .
 Midhinge
 .
 Mining engineering
 .
 Miller indices
 .
 Mobile robot
 .
 Mode
 .
 Modulus of elasticity
 .
 Molality
 .
 Molar concentration
 .
 Molar absorptivity
 .
 Molar mass
 .
 Molarity
 .
 Molding
 .
 Molecule
 .
 Molecular physics
 .
 Moment of inertia
 .
 Multibody system
 .
 Multidisciplinary design optimization
 .
 Mutual inductance
 .
 Muon
 .

N
 Nanoengineering
 .
 Nanotechnology
 .
 Navier–Stokes equations
 .
 Neutrino
 .
 Newtonian fluid
 .
 nth root
 To put a number of function to the exponential power of 1/n.
 Nuclear binding energy
 .
 Nuclear engineering
 .
 Nuclear physics
 .
 Nuclear potential energy
 .
 Nuclear power
 .
O
 Ohm
 The SI unit of electrical resistance.
 Ohm's law
 A law describing the relationship between resistance, current, and voltage.
 Optics
 The study of light.
 Organic chemistry
 The study of carbon compounds.
 Osmosis
 The spontaneous movement of molecules or ions through a semipermable membrane, tending to equalize concentration on both sides.
P
 Parallel circuit
 A circuit that begins and ends at the same node as another circuit.
 Parity (mathematics)
 .
 Parity (physics)
 .
 Paraffin
 A hydrocarbon compound, solid at room temperature.
 Particle accelerator
 .
 Particle displacement
 .
 Particle physics
 .
 Pascal's Law
 .
 Pendulum
 .
 Petroleum engineering
 .
 pH
 A logarithmic measure of the concentration of hydrogen ions in an acid or base solution.
 Phase (matter)
 .
 Phase (waves)
 .
 Phase equilibrium
 .
 Photon
 A particle with no rest mass that carries electromagnetic energy.
 Physical chemistry
 .
 Physical quantity
 .
 Physics
 .
 Planck constant
 .
 Plasma physics
 .
 Plasticity
 .
 Pneumatics
 The control of mechanical force and movement, generated by the application of compressed gas.
 Point estimation
 .
 Polyphase system
 An electrical system that uses a set of alternating currents at different phases.
 Power (electric)
 .
 Power (physics)
 .
 Power factor
 .
 Pressure
 The force per unit area .
 Probability
 .
 Probability distribution
 .
 Probability theory
 .
 Psi particle
 .
 Pulley
 .
 Pump
 .
Q
 Quantum electrodynamics
 .
 Quantum field theory
 .
 Quantum mechanics
 .
 Quantum physics
 .
R
 Regelation
 The phenomena of melting under pressure, then freezing when the pressure is reduced.
 Relative density
 .
 Relative velocity
 .
 Reliability engineering
 .
 Resistivity
 .
 Resistor
 .
 Reynolds number
 .
 Rheology
 .
 Rigid body
 .
 Robonaut
 A development project conducted by NASA to create humanoid robots capable of using space tools and working in similar environments to suited astronauts..
 Robotics
 .
 Rootmeansquare
 .
 Rootmeansquare speed
 .
 Rotational energy
 .
 Rotational speed
 .
S
 Safety data sheet
 .
 Sanitary engineering
 .
 Saturation (chemistry)
 .
 Saturated compound
 .
 Scalar (mathematics)
 .
 Scalar (physics)
 .
 Scalar multiplication
 .
 Screw
 .
 Series circuit
 .
 Servo
 A motor that moves to and maintains a set position under command, rather than continuously moving.
 Servomechanism
 An automatic device that uses errorsensing negative feedback to correct the performance of a mechanism.
 Shadow matter
 .
 Shear flow
 .
 Shear strength
 .
 Shear stress
 .
 Shortwave radiation
 .
 SI units
 .
 Signal processing
 .
 Simple machine
 .
 Siphon
 .
 Solid mechanics
 .
 Solidstate physics
 .
 Solid solution strengthening
 .
 Solubility
 .
 Sound
 .
 Special relativity
 .
 Specific heat
 .
 Specific gravity
 The ratio between the mass density of a substance to that of water.
 Specific volume
 .
 Specific weight
 The weight of a substance per unit volume.
 Spontaneous combustion
 .
 Stagnation pressure
 .
 Standard electrode potential
 .
 State of matter
 .
 Statics
 The study of forces in a nonmoving, rigid body.
 Statistics
 .
 Steam table
 .
 Stefan–Boltzmann law
 .
 Stewart platform
 a movable platform using six linear actuators, hence also known as a Hexapod.
 Stiffness
 .
 Stoichiometry
 .
 Strain
 .
 Strain hardening
 .
 Strength of materials
 .
 Stress
 .
 Stressstrain analysis
 .
 Stressstrain curve
 .
 Structural analysis
 .
 Structural load
 .
 Sublimation
 .
 Subsumption architecture
 a robot architecture that uses a modular, bottomup design beginning with the least complex behavioral tasks.
 Surface tension
 .
 Superconductor
 .
 Superhard material
 .
 Supersaturation
 .
 Surgical robot
 a remote manipulator used for keyhole surgery.
T
 Tangential acceleration
 .
 Technical standard
 .
 Temperature
 The measure of heat energy in an object or fluid.
 Tempering (metallurgy)
 Heat treatment to alter the crystal structure of a metal such as steel.
 Tensile force
 Pulling force, tending to lengthen an object.
 Tensile modulus
 .
 Tensile strength
 .
 Tensile testing
 .
 Tension member
 .
 Thermal conduction
 .
 Thermal equilibrium
 .
 Thermal radiation
 .
 Thermodynamics
 The science of the flow of heat.
 Theory of relativity
 .
 Thévenin's theorem
 .
 Threephase
 Electric power using three alternating currents, displaced in time.
 Torque
 Twisting force.
 Torsional vibration
 .
 Toughness
 .
 Trajectory
 .
 Transducer
 .
 Transformer
 .
 Trigonometric functions
 .
 Trigonometry
 .
 Trimean
 .
 Triple point
 .
 Trouton's rule
 .
 Truncated mean
 .
 Truss
 .
 Turbine
 .
 Turbomachinery
 .
 Turbulence
 .
U
 Ultimate tensile strength
 .
 Uncertainty principle
 .
 Unicode
 .
 Unit vector
 .
 Unsaturated compound
 .
 Upthrust
 .
 Utility frequency
 .
V
 Vacuole
 .
 Vacuum
 An absence of mass in a volume.
 Valence
 .
 Valence band
 .
 Valence bond theory
 .
 Valence electron
 .
 Valence shell
 .
 Valve
 A device for controlling fluid flow.
 van der Waals equation
 .
 van der Waals force
 .
 van 't Hoff equation
 .
 van 't Hoff factor
 .
 Variable capacitor
 .
 Variable resistor
 .
 Vector space
 .
 Venturi effect
 .
 Vibration
 .
 Viscoelasticity
 .
 Viscosity
 .
 Voltampere
 .
 Voltampere reactive
 .
 Volta potential
 .
 Voltage
 .
 Volumetric flow rate
 .
 von Mises yield criterion
 .
W
 Watt
 The SI unit of power, rate of doing work.
 Wave
 .
 Wavelength
 .
 Wedge
 .
 Weighted mean
 .
 Wetbulb temperature
 The temperature of a wetted thermometer with an air current across it. Used in psychrometry. .
 Wheel and axle
 .
 Winsorized mean
 .
X
 Xcoordinate
 .
Y
 Ycoordinate
 .
 Yield
 .
 Young's modulus
 .
Z
 Zero Defects
 .
 Zeroth law of thermodynamics
 .
See also
References
Glossaries of science and engineering

