Other forms: shells, shelling, shelled
A shell is the hard outer case something grows inside — the snail's spiral house, the thin coat you crack off a boiled egg, the woody jacket round a walnut. You pick shells up off the beach, you tap an egg shell on the side of the pan, you throw the nut shells in the bin.
The word travels a long way from the beach. A shell is also an artillery round, a metal case packed with explosive, and to shell a town is to bombard it with those. Anything that is an outside with nothing left inside is a shell: the burnt-out shell of a house, the shell of a company that no longer trades. As a verb it means taking something out of its case — you shell peas, you shell prawns. In computing, the shell is the text program that takes your typed commands and passes them to the machine. Shell out means to pay, and it carries a small groan about the price.
1nounshellThe hard outer covering of an egg, a nut, a seed, or an animal such as a snail, crab or tortoise.
“The chicks broke through the shell one at a time.”
synonyms: casing, husk
2nounemptyThe empty case of a sea creature, washed up and picked up on a beach.
“She filled her pockets with shells and flat white stones.”
3nounmetalA metal case filled with explosive, fired from a large gun.
“A shell landed in the square and took out half the market.”
4verbplaceTo fire explosive shells at a place.
“The city was shelled for three nights running.”
5nounstructureThe outer structure of something with nothing left inside it.
“After the fire the factory was a blackened shell.”
6verbpodTo take something out of its shell, pod or husk.
“He sat on the step shelling peas into a bowl.”
7nounprogramThe program that takes typed commands and hands them to a computer's operating system.
“Open a shell and run the command from there.”
Too few real examples of this word to estimate which sense is commonest.
shell is a hard outer covering.
Shell goes back through Middle English schelle to Old English sċell, from Proto-Germanic *skaljō, which covered shell, husk, rind and peel alike, and behind that a Proto-Indo-European root *(s)kelH-, 'to cut, to split'. The shell is named for the splitting: the thing that comes off. Its cousins are everywhere — Dutch schil for peel, Icelandic skel, French écaille for a scale.
Old English
sċiell
Middle English
schelle
English, today
shell
From Middle English schelle, from Old English sċiell. From Middle English schelle, from Old English sċel, sċell, sċiell, sċil, sċill, sċyl, sċyll, from Proto-West Germanic skallju, from Proto-Germanic skaljō (“shell; husk; rind; peel”), from Proto-Indo-European (s)kelH- (“to cut; to separate, split”). 2
Etymology from Wiktionary, CC BY-SA