/ Dictionary / Index P prototrophic: Meaning and Definition of Find definitions for: pro•to•troph•ic Pronunciation: (prō"tu-trof'ik, -trō'fik), [key] — adj. (esp. of certain bacteria) requiring only inorganic substances for growth. (of certain microorganisms) requiring no specific nutriments for growth. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. prototroph prototype Related Content Daily Word Quiz: feline Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language