Shell may refer to:

Architecture and design

* Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure

Science

Biology

Seashell A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washe ...

, a hard outer layer of a marine animal, found on beaches *

Eggshell An eggshell is the outer covering of a hard-shelled egg and of some forms of eggs with soft outer coats. Diversity Worm eggs Nematode eggs present a two layered structure: an external vitellin layer made of chitin that confers mechanical ...

* Nutshell *

Exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the ...

, an external covering of some animals ** Mollusc shell *** Bivalve shell ***

Gastropod shell The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium s ...

** Shell, of a brachiopod ** Turtle shell

Physics and chemistry

* Electron shell or a principal energy level of electrons outside an atom's nucleus *

Nuclear shell model In nuclear physics, atomic physics, and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels. The first shell mod ...

, a principal energy level of nucleons within an atom's nucleus * On shell and off shell, quantum field theory concepts depending on whether classical equations of motion are obeyed

Mathematics

* Spherical shell

Organisations

Shell plc Shell plc is a British multinational oil and gas company headquartered in London, England. Shell is a public limited company with a primary listing on the London Stock Exchange (LSE) and secondary listings on Euronext Amsterdam and the New Yo ...

, a British multinational oil and gas company **

Shell USA Shell USA, Inc. (formerly Shell Oil Company, Inc.) is the United States-based wholly owned subsidiary of Shell plc, a UK-based transnational corporation " oil major" which is amongst the largest oil companies in the world. Approximately 18,000 ...

** Shell Australia ** Shell Canada ** Shell Nigeria * Shell corporation, a type of company that serves as a vehicle for business transactions

Computing

* Shell (computing), a type of user interface **

Command-line interface A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

, sometimes referred to as command shell ** List of command-line interpreters, programs occasionally referred to as shells ** Web shell, interface that enables a web server to be remotely accessed * Read–eval–print loop, also known as a language shell * Shell account, a user account on a remote server *

Secure Shell The Secure Shell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. SSH applications are based on a ...

, cryptographic network protocol * Shellsort or Shell sort, a sorting algorithm by Donald Shell * Shell, an empty

expert system In artificial intelligence, an expert system is a computer system emulating the decision-making ability of a human expert. Expert systems are designed to solve complex problems by reasoning through bodies of knowledge, represented mainly as if� ...

Entertainment

* ''Shell'' (film) *

Shell (theater) In theater, a shell (also known as an acoustical shell, choral shell or bandshell) is a curved, hard surface designed to reflect sound towards an audience. Often shells are designed to be removable, either rolling away on wheels or lifting into ...

, a curved surface for reflecting sound *

The Shells The Shells were an American doo wop ensemble formed in Brooklyn, New York, United States, in 1957. The group scored a US pop hit in 1957 with the song "Baby Oh Baby", released on Johnson Records; the song cracked the Top 30. Further singles p ...

, a musical group * "Shells" (''Angel''), a TV episode * Shell, a receptacle used in the

Shell game The shell game (also known as thimblerig, three shells and a pea, the old army game) is often portrayed as a gambling game, but in reality, when a wager for money is made, it is almost always a confidence trick used to perpetrate fraud. In conf ...

Places

Shell, Ecuador Shell (also Shell Mera) is a city located on the western edge of the Ecuadorian Amazon and in the eastern foothills of the Andes. It is located about southeast of Quito, and roughly west of the provincial capital, Puyo. Its name comes from the R ...

Shell, Wyoming Shell is a census-designated place (CDP) in Big Horn County, Wyoming, United States. The population was 83 at the 2010 Census. The community is named for the abundance of fossil shells located in the area. Nearby exposed formations such as the ...

, United States *

Shell Lake (disambiguation) Canada * Shell Lake, Saskatchewan, a community in Saskatchewan ** Shell Lake murders * Big Shell Lake, a lake in Saskatchewan * Shell Lake (Saskatchewan), a lake in Saskatchewan * Rural Municipality of Shell Lake No. 495 * Inuvik/Shell Lake Wate ...

, several places

Weaponry

Shell (projectile) A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. Modern usage s ...

, an explosive device fired from artillery *

Shotgun shell A shotgun shell, shotshell or simply shell is a type of rimmed, cylindrical (straight-walled) cartridges used specifically in shotguns, and is typically loaded with numerous small, pellet-like spherical sub- projectiles called shot, fired thro ...

, a type of shotgun ammunition

Persons with the surname Shell

* Art Shell (born 1946), American football player and coach * Brandon Shell (born 1992), American football player *

Donald Shell Donald L. Shell (March 1, 1924 – November 2, 2015) was an American computer scientist who designed the Shellsort sorting algorithm. He acquired his Ph.D. in mathematics from the University of Cincinnati in 1959, and published the Shellsort algo ...

(1924–2015), American computer scientist * Donnie Shell (born 1952), American football player *

George W. Shell George Washington Shell (November 13, 1831 – December 15, 1899) was a U.S. Representative from South Carolina. Life Born near Laurens, South Carolina, Shell attended the common schools and Laurens Academy. He engaged in agricultural pursu ...

(1831–1899), U.S. Representative from South Carolina *

Karl Shell Karl Shell (born May 10, 1938) is an American theoretical economist, specializing in macroeconomics and monetary economics. Shell received an A.B. in mathematics from Princeton University in 1960. He earned his Ph.D. in economics in 1965 at St ...

(born 1938), American economist

Other uses

Racing shell In watercraft, a racing shell (also referred to as just a ''fine boat'' (UK) or just ''shell'') is an extremely narrow, and often comparatively long, rowing boat specifically designed for racing or exercise. It is outfitted with long oars, outrigg ...

, a watercraft *

Shell (machinery) A plain bearing, or more commonly sliding contact bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing), is the simplest type of bearing, comprising just a bearing surface and no rolli ...

, each half of a two-piece plain bearing *

Coverage shell Zone coverage (also referred to as a zone defense) is a defense scheme in gridiron football used to protect against the pass. Zone coverage schemes require the linebackers and defensive backs to work together to cover certain areas of the field ...

, the number of defenders guarding the deep portion of the field in American football *

Conchiglie Conchiglie (), commonly known as "shells" or "seashells", is a type of pasta. It is usually sold in the plain durum wheat variety, and also in colored varieties which use natural pigments, such as tomato extract, squid ink or spinach extract. Th ...

, a type of pasta