/ Dictionary / Index P phototropism: Meaning and Definition of Find definitions for: pho•tot•ro•pism Pronunciation: (fō-to'tru-piz"um, fō"tō-trō'piz-um), [key] — n. Bot. phototropic tendency or growth. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phototropism (Thesaurus) phototropic phototube Related Content Daily Word Quiz: crutiny Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language