/ Dictionary / Index G grand unification theory: Meaning and Definition of Find definitions for: grand' unifica'tion the"ory Pronunciation: [key] — Physics. Physics. a possible future quantum field theory that would encompass both the electroweak theory and quantum chromodynamics. Abbr.: GUT Also called Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. granduncle Grandview 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