/ Dictionary / Index G ground state: Meaning and Definition of Find definitions for: ground' state" Pronunciation: [key] — Physics. Physics. the state of least energy of a particle, as an atom, or of a system of particles. Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. ground squirrel ground station Related Content Daily Word Quiz: lyre Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language