/ Dictionary / Index C complementarity: Meaning and Definition of Find definitions for: com•ple•men•tar•i•ty Pronunciation: (kom"plu-men-tar'i-tē), [key] — n. the quality or state of being complementary. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: complementarity (Thesaurus) complemental complementarity principle Related Content Daily Word Quiz: sumptuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language