- a hard outer covering, as of a turtle, mollusk, insect, egg, fruit, seed, etc.
- something like or suggestive of a shell in being hollow, empty, or simply a covering or framework, as the hull of a boat, a hollow pastry or unfilled pie crust, the framework of a building, a structure with an arched or hemispherical roof or back, a tapered beer glass, etc.
- a shy, reserved, or uncommunicative attitude or manner: to come out of one's shell
- ☆ a woman's simple sleeveless blouse or sweater
- ☆ a long, narrow, thin-hulled racing boat rowed usually by a team of oarsmen
- an explosive artillery projectile containing high explosives and sometimes shrapnel, chemicals, etc.
- ☆ a cartridge for small arms or small artillery, consisting of a metal, paper, or plastic case holding the primer, powder charge, and shot or bullet
- a pyrotechnic cartridge which explodes high in the air
- a mollusk
- Chem., Physics
- any of the spherical or elliptical orbits of electrons around the nucleus of an atom, each with the same principal quantum number and about the same energy
- the space taken up by such an orbit
- a grouping of like nucleons of approximately the same energy in the nucleus
ME schelle < OE sciel, akin to MDu schelle < IE base *(s)kel-: see shelf