- any of up to seven energy levels on which an electron may exist within an atom, the energies of the electrons on the same level being equal and on different levels being unequal.
- a group of nucleons of approximately the same energy.
- a scab on the surface of an ingot.
- a length of unfinished tubing.
- a pierced forging.
- a hollow object made by deep drawing.
verb (used with object)
verb (used without object)
Origin of shell
Related formsshell-less, adjectiveshell-like, adjectivede-shell, verb (used with object)
British Dictionary definitions for shell out (1 of 2)
Word Origin for shell out
British Dictionary definitions for shell out (2 of 2)
- a class of electron orbits in an atom in which the electrons have the same principal quantum number and orbital angular momentum quantum number and differences in their energy are small compared with differences in energy between shells
- an analogous energy state of nucleons in certain theories (shell models) of the structure of the atomic nucleus
Derived Formsshell-less, adjectiveshelly, adjective
Word Origin for shell
Science definitions for shell out
- The usually hard outer covering of certain animals, such as mollusks, insects, and turtles.
- The hard outer covering of a bird's egg.
- The hard outer covering of a seed, nut, or fruit.
- A set of electron orbitals that have nearly the same energy. Electrons in outer shells have greater energy than those in shells closer to the nucleus. Elements in the Periodic Table range from the lightest elements with electrons normally occupying one shell (hydrogen and helium) to the heaviest, with electrons in seven shells (radium and uranium, for instance). See more at atomic spectrum orbital subshell. See Note at metal.
- 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.
Idioms and Phrases with shell out (1 of 2)
Pay, hand over, as in We had to shell out $1,000 for auto repairs. This expression transfers taking a seed such as a pea or nut out of its pod or shell to taking money out of one's pocket. [Colloquial; c. 1800]
Idioms and Phrases with shell out (2 of 2)
In addition to the idiom beginning with shell
- shell out
- in one's shell