/ Dictionary / Index S synoicous: Meaning and Definition of Find definitions for: syn•oi•cous Pronunciation: (si-noi'kus), [key] — adj. Bot. having male and female flowers on one head, as in many composite plants. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: synoicous (Thesaurus) synodic month synonym Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language