/ Dictionary / Index K K-shell: Meaning and Definition of Find definitions for: K-shell Pronunciation: (kā'shel"), [key] — n. Physics. the first shell of electrons surrounding the nucleus of an atom and containing, when filled, two electrons having principal quantum number 1. Cf. L-shell, M-shell, N-shell. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Kshatriya ksi Related Content Daily Word Quiz: morose Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language