/ Dictionary / Index S subatomic: Meaning and Definition of Find definitions for: sub•a•tom•ic Pronunciation: (sub"u-tom'ik), [key] — adj. Physics. of or pertaining to a process that occurs within an atom. noting or pertaining to a particle or particles contained in an atom, as electrons, protons, or neutrons. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: subatomic (Thesaurus) subatom subaudition Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language