/ Dictionary / Index S sumac: Meaning and Definition of Find definitions for: su•mac Pronunciation: (s'mak, sh'-), [key] — n. any of several shrubs or small trees belonging to the genus Rhus of the cashew family, having milky sap, compound leaves, and small, fleshy fruit. a preparation of the dried and powdered leaves, bark, etc., of certain species of Rhus, esp. R. coriaria of southern Europe, used esp. in tanning. the wood of these trees. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: sumac (Thesaurus) sum sumac wax 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