/ Dictionary / Index H heliotropin: Meaning and Definition of Find definitions for: he•li•o•tro•pin Pronunciation: (hē"lē-u-trō'pin, hē"lē-o'tru-pin), [key] — n. piperonal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. heliotropic heliotropism Related Content Daily Word Quiz: stringent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language