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shell (shĕl)
a. The usually hard outer covering that encases certain organisms, such as insects, turtles, and most mollusks.
b. A similar outer covering on a nut or seed.
c. A similar outer covering on certain eggs, such as those of birds and reptiles; an eggshell.
d. The material that constitutes such a covering.
2. Something resembling or having the form of a shell, especially:
a. An external, usually hard, protective or enclosing case or cover.
b. A framework or exterior, as of a building.
c. A thin layer of pastry.
d. The external part of the ear.
3. Nautical
a. The hull of a ship.
b. A light, long, narrow racing boat propelled by rowers.
4. A small glass for beer.
a. An artillery projectile containing an explosive charge.
b. A metal or cardboard case containing the charge and primer for a piece of firearms ammunition, especially one also containing shot and fired from a shotgun.
6. An attitude or a manner adopted to mask one's true feelings or to protect one from perceived or real danger: Embarrassed, she withdrew into a shell.
7. Physics
a. A set of electron orbitals having nearly the same energy and sharing the same first quantum number.
b. Any of the stable states of other particles or collections of particles (such as the nucleons in an atomic nucleus) at a given energy or small range of energies.
a. A usually sleeveless and collarless, typically knit blouse.
b. A thin, usually waterproof or windproof outer garment for the upper body.
9. Computers A program that works with the operating system as a command processor, used to enter commands and initiate their execution.
10. A company or corporation created by a second company or corporation for the purposes of facilitating a particular transaction, especially one that is intended to be concealed.
v. shelled, shell·ing, shells
a. To remove the shell of; shuck: shell oysters.
b. To remove from a shell: shell peas.
2. To separate the kernels of (corn) from the cob.
3. To fire shells at; bombard.
a. To defeat decisively.
b. Baseball To hit the pitches of (a pitcher) hard and with regularity: shelled the pitcher for eight runs in the first inning.
1. To shed or become free of a shell.
2. To look for or collect shells, as on a seashore: spent the day shelling on Cape Cod.
Phrasal Verb:
shell out Informal
To hand over; pay: had to shell out $500 in car repairs.

[Middle English, from Old English scell; see skel-1 in the Appendix of Indo-European roots.]

shell adj.
sheller n.

The American Heritage® Dictionary of the English Language, Fifth Edition copyright ©2022 by HarperCollins Publishers. All rights reserved.

Indo-European & Semitic Roots Appendices

    Thousands of entries in the dictionary include etymologies that trace their origins back to reconstructed proto-languages. You can obtain more information about these forms in our online appendices:

    Indo-European Roots

    Semitic Roots

    The Indo-European appendix covers nearly half of the Indo-European roots that have left their mark on English words. A more complete treatment of Indo-European roots and the English words derived from them is available in our Dictionary of Indo-European Roots.