/ Dictionary / Index P phytochrome: Meaning and Definition of Find definitions for: phy•to•chrome Pronunciation: (fī'tu-krōm"), [key] — n. Bot. a plant pigment that is associated with the absorption of light in the photoperiodic response and that may regulate various types of growth and development. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. phytochemistry phytocide Related Content Daily Word Quiz: eureka Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language