Contraction may refer to:

Linguistics

Contraction (grammar) A contraction is a shortened version of the spoken and written forms of a word, syllable, or word group, created by omission of internal letters and sounds. In linguistic analysis, contractions should not be confused with crasis, abbreviation ...

, a shortened word *

Poetic contraction Poetic contractions are contractions of words found in poetry but not commonly used in everyday modern English. Also known as elision or syncope, these contractions are usually used to lower the number of syllables in a particular word in order ...

, omission of letters for poetic reasons *

Elision In linguistics, an elision or deletion is the omission of one or more sounds (such as a vowel, a consonant, or a whole syllable) in a word or phrase. However, these terms are also used to refer more narrowly to cases where two words are run toget ...

, omission of sounds **

Syncope (phonology) In phonology, syncope (; from grc, , , cutting up) is the loss of one or more sounds from the interior of a word, especially the loss of an unstressed vowel. It is found in both synchronic and diachronic analyses of languages. Its opposite, whe ...

, omission of sounds in a word *

Synalepha A synalepha or synaloepha is the merging of two syllables into one, especially when it causes two words to be pronounced as one. The original meaning in Ancient Greek is more general than modern usage and includes coalescence of vowels within a w ...

, merged syllables **

Synaeresis In linguistics, synaeresis (; also spelled syneresis) is a phonological process of sound change in which two adjacent vowels within a word are ''combined'' into a single syllable. The opposite process, in which two adjacent vowels are pronounce ...

, combined vowels **

Crasis Crasis (; from the Greek , "mixing", "blending"); cf. , "I mix" ''wine with water''; '' kratēr'' "mixing-bowl" is related. is a type of contraction in which two vowels or diphthongs merge into one new vowel or diphthong, making one word out of t ...

, merged vowels or diphthongs

Mathematics and logic

Contraction (operator theory) In operator theory, a bounded operator ''T'': ''X'' → ''Y'' between normed vector spaces ''X'' and ''Y'' is said to be a contraction if its operator norm , , ''T'' , , ≤ 1. This notion is a special case of the concept of a contractio ...

, in operator theory, state of a bounded operator between normed vector spaces after suitable scaling *

Contraction hierarchies In computer science, the method of contraction hierarchies is a speed-up technique for finding the shortest-path in a graph. The most intuitive applications are car-navigation systems: a user wants to drive from A to B using the quickest possible ...

, in applied mathematics, a technique to speed up shortest-path routing *

Contraction mapping In mathematics, a contraction mapping, or contraction or contractor, on a metric space (''M'', ''d'') is a function ''f'' from ''M'' to itself, with the property that there is some real number 0 \leq k < 1 such that for all ''x'' and ...

, a type of function on a metric space *

Edge contraction In graph theory, an edge contraction is an operation that removes an edge from a graph while simultaneously merging the two vertices that it previously joined. Edge contraction is a fundamental operation in the theory of graph minors. Vertex ide ...

or vertex contraction, graph operations used in graph theory *

Tensor contraction In multilinear algebra, a tensor contraction is an operation on a tensor that arises from the natural pairing of a finite-dimensional vector space and its dual. In components, it is expressed as a sum of products of scalar components of the tenso ...

, an operation on one or more tensors that arises from the natural pairing of a finite-dimensional vector space and its dual * Left contraction and right contraction of multivectors in a geometric algebra, extensions of the inner product * One of the rules of

conditional independence In probability theory, conditional independence describes situations wherein an observation is irrelevant or redundant when evaluating the certainty of a hypothesis. Conditional independence is usually formulated in terms of conditional probabil ...

, in probability *

Contraction (logic) In proof theory, a structural rule is an inference rule that does not refer to any logical connective, but instead operates on the judgment or sequents directly. Structural rules often mimic intended meta-theoretic properties of the logic. Logics ...

, a structural rule in proof theory

Medicine

Muscle contraction Muscle contraction is the activation of tension-generating sites within muscle cells. In physiology, muscle contraction does not necessarily mean muscle shortening because muscle tension can be produced without changes in muscle length, such as ...

, the physiological condition of a muscle which generates tension (traction) at its origin and insertion **

Uterine contraction Uterine contractions are muscle contractions of the uterine smooth muscle that occur during the menstrual cycle and labour. Uterine contractions occur throughout the menstrual cycle in the non-pregnant state and throughout gestation. Throughout m ...

, contraction of the uterus, such as during childbirth *

Contractility Contractility refers to the ability for self-contraction, especially of the muscles or similar active biological tissue *Contractile ring in cytokinesis *Contractile vacuole *Muscle contraction **Myocardial contractility *See contractile cell for ...

, the intrinsic ability of the heart/myocardium to contract *

Wound contraction Wound healing refers to a living organism's replacement of destroyed or damaged tissue by newly produced tissue. In undamaged skin, the epidermis (surface, epithelial layer) and dermis (deeper, connective layer) form a protective barrier agai ...

, a stage in wound healing

Other uses

Contraction (economics) In economics, a recession is a business cycle contraction when there is a general decline in economic activity. Recessions generally occur when there is a widespread drop in spending (an adverse demand shock). This may be triggered by various ...

, a general slowdown in economic activity; the opposite of economic expansion *

Contraction (physics) Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions. Temperature is a monotonic function of the average molecular kinetic ...

, change in the volume of matter in response to a change in temperature *

Lanthanide contraction The lanthanide contraction is the greater-than-expected decrease in atomic radii/ionic radii of the elements in the lanthanide series from atomic number 57, lanthanum, to 71, lutetium, which results in smaller than otherwise expected atomic rad ...

, the decrease in size of the ionic radius of lanthanide elements with their growing atomic number * ''Contracted'' (film), a 2013 horror thriller film by Eric England and its sequel '' Contracted: Phase II'' (2015) which directed by Josh Forbes

Linguistics

Mathematics and logic

Medicine

Other uses

See also