/ Dictionary / Index P phyco-: Meaning and Definition of Find definitions for: phyco- Pronunciation: [key] a combining form meaning “seaweed,” “algae,” used in the formation of compound words: phycochrome. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Phumiphon Aduldet phycobiont Related Content Daily Word Quiz: deleterious Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language