/ Dictionary / Index P photobiology: Meaning and Definition of Find definitions for: pho•to•bi•ol•o•gy Pronunciation: (fō"tō-bī-ol'u-jē), [key] — n. the study of the effects of light on biological systems. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. photoautotroph photobiotic Related Content Daily Word Quiz: procrastinate Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language