/ Dictionary / Index I invariant: Meaning and Definition of Find definitions for: in•var•i•ant Pronunciation: (in-vâr'ē-unt), [key] — adj. unvarying; invariable; constant. normal (def. 5e). —n. a quantity or expression that is constant throughout a certain range of conditions. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: invariant (Thesaurus) invariable invasion Related Content Daily Word Quiz: acquiesce Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language