A piece of software, usually a separate program, that provides direct communication between the user and the operating system. Examples of shells are Macintosh Finder and the MS-DOS command interface program COMMAND.COM. See also Bourne shell, C shell, Finder, Korn shell. Compare kernel.

ETYM Old Eng. band, bond, Icel. band; akin to German, Swed., and Dutch band, Old High Germ. bant, Goth. bandi, Skr. bandha a binding, bandh to bind, for bhanda, bhandh, also to Eng. bend, bind. Related to Bind, Bend, Bond, Bandy.
(Homonym: banned).
1. A strip or stripe of a contrasting color or material; SYN. banding, stripe.
2. A stripe of contrasting color; SYN. stria, striation.
3. Band of radio frequencies for e.g. transmitting a TV signal; SYN. frequency band.
4. A group of musicians.
5. A strip wrapped around something to hold it together.
6. Something elongated that is worn around the body or one of the limbs.

ETYM Latin crusta: cf. Old Fren. crouste, French croûte.
The outermost part of the structure of Earth, consisting of two distinct parts, the oceanic crust and the continental crust. The oceanic crust is on average about 10 km/6.2 mi thick and consists mostly of basaltic types of rock. By contrast, the continental crust is largely made of granite and is more complex in its structure. Because of the movements of plate tectonics, the oceanic crust is in no place older than about 200 million years. However, parts of the continental crust are over 3 billion years old.
Beneath a layer of surface sediment, the oceanic crust is made up of a layer of basalt, followed by a layer of gabbro. The composition of the oceanic crust overall shows a high proportion of silicon and magnesium oxides, hence named sima by geologists. The continental crust varies in thickness from about 40 km/25 mi to 70km/45 mi, being deeper beneath mountain ranges. The surface layer consists of many kinds of sedimentary and igneous rocks. Beneath lies a zone of metamorphic rocks built on a thick layer of granodiorite. Silicon and aluminium oxides dominate the composition and the name sial is given to continental crustal material.
1. A hard outer layer that covers something; SYN. incrustation, encrustation.
2. The outer layer of the Earth; SYN. Earth's crust.
3. The trait of being rude and impertinent; inclined to take liberties; SYN. gall, impertinence, impudence, insolence, cheekiness, freshness.

ETYM Old Eng. hul, hol, shell, husk, as. hulu; akin to German hülle covering, husk, case, hüllen to cover, Goth. huljan to cover, as. helan to hele, conceal. Related to Hele, Hell.
1. Dry outer covering of a fruit or seed or nut.
2. Persistent enlarged calyx at base of e.g. a strawberry or raspberry.
3. The frame or body of ship.
4. A large fishing port.

ETYM Prob. for hulsk, and from the same root as hull a husk. Related to Hull a husk.
Outer membranous covering of some fruits or seeds.

ETYM Latin integumentum, from integere to cover; pref. in- in, on + tegere to cover: cf. French intégument. Related to n-, and Tegument.
An outer protective covering such as a cuticle or seed coat or rind or shell.
An external covering or coating.
In seed-producing plants, the protective coat surrounding the ovule. In flowering plants there are two, in gymnosperms only one. A small hole at one end, the micropyle, allows a pollen tube to penetrate through to the egg during fertilization.

Thin plate or layer; flake.
In flowering plants (angiosperms), the blade of the leaf on either side of the midrib. The lamina is generally thin and flattened, and is usually the primary organ of photosynthesis. It has a network of veins through which water and nutrients are conducted. More generally, a lamina is any thin, flat plant structure, such as the thallus of many seaweeds.

1. A flattened rigid plate forming part of the body covering of many animals
2. A series of notes differing in pitch according to a specific scheme (usually within an octave); SYN. musical scale.
3. A specialized leaf or bract that protects a bud or catkin; SYN. scale leaf.
4. The ratio between the size of something and a representation of it
5. An indicator having a graduated sequence of marks.
6. An instrument for weighing; shows amount of mass; SYN. weighing machine.
7. An ordered reference standard:; SYN. scale of measurement, graduated table, ordered series.
8. Relative magnitude
9. A thin flake of dead epidermis shed from the surface of the skin; SYN. scurf.

ETYM as. scealy, scalu. Related to Scalme, Shell.
A sedimentary rock formed by the deposition of successive layers of clay.
Laminated rock of consolidated clay or mud.
Fine-grained and finely layered sedimentary rock composed of silt and clay. It is a weak rock, splitting easily along bedding planes to form thin, even slabs (by contrast, mudstone splits into irregular flakes). Oil shale contains kerogen, a solid bituminous material that yields petroleum when heated.

ETYM as. sceard, properly a p. p. from the root of scearn to shear, to cut; akin to Dutch schaard a fragment, German scharte a notch, Icel. skarth. Related to Shear, Sherd.
1. A broken piece of a brittle artifact; SYN. sherd, fragment.
2. Piece of broken pottery; elytrum.
3. Highly angular curved glass fragments of tuffaceous sediments.

ETYM Old Eng. shelle, schelle, as. scell, scyll; akin to Dutch shel, Icel. skel, Goth. skalja a tile, and Eng. skill. Related to Scale of fishes, Shale, Skill.
1. A rigid covering that envelops an object.
2. The exterior covering of a bird's egg; SYN. eggshell.
3. The hard usually fibrous outer layer of some fruits especially nuts.
4. The outer covering or housing of something; SYN. case, casing.
5. A very light narrow racing boat; SYN. racing shell.
The hard outer covering of a wide variety of invertebrates. The covering is usually mineralized, normally with large amounts of calcium. The shell of birds' eggs is also largely made of calcium.
Trade name of the Anglo-Dutch oil-development and exploration concern Royal Dutch/Shell Group, one of the world's biggest companies, formed 1907.
Shell is the world's largest oil and gas producer, with the largest oil reserves, and is responsible for 5% of the world's oil and gas production. It has 2,000 operating companies worldwide. It is also the world's largest retailer, with (1994) 40,000 gasoline stations in 100 countries. Its sales turnover in 1992 amounted to more than the gross national product of any country except the 23 richest.
The company abandoned plans to dump a disused oil-storage platform in the north Atlantic Ocean June 1995 in the face of widespread protests spearheaded by the environmentalist group Greenpeace.
The business originated in the early 19th century with a curio shop in E London that sold shell ornaments; by 1830 the dealer, Marcus Samuel, had built up an international trade in copra and oriental artifacts. From 1897 the company dealt in oil and kerosene (paraffin oil) and was consolidated as the Shell Transport and Trading Company, amalgamating with the Royal Dutch Petroleum Company 1907.

ETYM Icel. skinn; akin to Swed. skinn, Dan. skind, as. scinn, German schined to skin.
1. An outer surface (usually thin).
2. The tissue forming the hard outer layer of e.g. a fruit; SYN. rind.
3. A person's skin regarded as their life.
4. A container for liquids that is made from the skin of an animal.

A protective case enclosing eggs; ootheca — called also egg capsule.

1. The shell or exterior covering of an egg. Also used figuratively for anything resembling an eggshell.
2. A smooth, white, marine, gastropod shell of the genus Ovulum, resembling an egg in form. egg shell, egg-shell

1. The shell or exterior covering of an egg. Also used figuratively for anything resembling an eggshell.
2. A smooth, white, marine, gastropod shell of the genus Ovulum, resembling an egg in form. egg shell, egg-shell

1 — used as an attributive form of craps
2. A throw of 2, 3, or 12 in the game of craps losing the shooter his bet unless he has a point — called also craps — compare natural

Any mainly aquatic arthropod usually having a segmented body and chitinous exoskeleton.
Animal with hard shell.
One of the class of arthropods that includes crabs, lobsters, shrimps, woodlice, and barnacles. The external skeleton is made of protein and chitin hardened with lime. Each segment bears a pair of appendages that may be modified as sensory feelers (antennae), as mouthparts, or as swimming, walking, or grasping structures.

Meat of edible aquatic invertebrate with a shell (especially a mollusk or crustacean).
Popular name for mollusks and crustaceans, including the whelk and periwinkle, mussel, oyster, lobster, crab, and shrimp.
shell-fish.

Class of mandibulate arthropods including: lobsters; crabs; shrimps; woodlice; barnacles; decapods; water fleas; Also called: class Crustacea.

ETYM New Lat. crustaceous. Related to crustacea.
Being or having or resembling a hard crust or shell.