/ Dictionary / Index H histioid: Meaning and Definition of Find definitions for: his•ti•oid Pronunciation: (his'tē-oid"), [key] — adj. histoid. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. histidine histo- Related Content Daily Word Quiz: arid Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language