/ Dictionary / Index P phytoplankton: Meaning and Definition of Find definitions for: phy•to•plank•ton Pronunciation: (fī"tu-plangk'tun), [key] — n. the aggregate of plants and plantlike organisms in plankton. Cf. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: phytoplankton (Thesaurus) phytophthora phytoplasm Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language