/ Dictionary / Index H hexad: Meaning and Definition of Find definitions for: hex•ad Pronunciation: (hek'sad), [key] — n. the number six. a group or series of six. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: hexad (Thesaurus) hexacosanoic acid hexadecanoic acid Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language