• (RP) IPA: /ˈs(j)uːmæk/, /ˈʃuː-/
• (GA) IPA: /ˈsuːˌmæk/, /ˈsu-/

sumac (uncountable)

1. Any of various shrubs or small trees of the genus Rhus and other genera in Anacardiaceae, particularly the elm-leaved sumac, Sicilian sumac, or tanner's sumac (Rhus coriaria).
   • 1854 August 8, Henry D[avid] Thoreau, “Sounds”, in Walden; or, Life in the Woods, Boston, Mass.: Ticknor and Fields, OCLC 4103827 ↗, page 139 ↗:

     A young forest growing up under your windows, and wild sumachs and blackberry vines breaking through into your cellar; sturdy pitch-pines rubbing and creaking against the shingles for want of room, their roots reaching quite under the house.

   • 1876, Mark Twain [pseudonym; Samuel Langhorne Clemens], chapter XXIX, in The Adventures of Tom Sawyer, Hartford, Conn.: The American Publishing Company, OCLC 1000326417 ↗, page 222 ↗:

     They plunged into the narrow path between the tall sumach bushes, and were at once hidden in the gloom.

2. dried#Adjective|Dried and chopped-up leaf#Noun|leaves and stem#Noun|stems of a plant#Noun|plant of the genus Rhus, particularly the tanner's sumac (see sense 1), used for dye#Verb|dyeing and tan#Verb|tanning leather or for medicinal purposes.
   • 1584, William Barret[t], “The Money and Measures of Babylon, Balsara, and the Indies, with the Customes, &c. Written from Aleppo in Syria, Anno 1584”, in Richard Hakluyt, The Principall Navigations, Voiages, and Discoveries of the English Nation, […], imprinted at London: By George Bishop and Ralph Newberie, deputies to Christopher Barker, printer to the Queen's Most Excellent Majestie, published 1589, OCLC 753964576 ↗, page 219 ↗:

     A declaration of the places whence the goods ſubſcribed doe come. [...] Sumack, from Cyprus.

3. A sour spice#Noun|spice popular in the Eastern Mediterranean, made from the berries of tanner's sumac.

• French: sumac
• German: Sumach, Rhus
• Italian: sommacco
• Portuguese: sumagre
• Russian: сума́х
• Spanish: zumaque

• German: Sumak
• Portuguese: sumagre
• Russian: сума́х
• Spanish: zumaque

sumac (sumacs, present participle sumacing; past and past participle sumaced)

1. (transitive) To apply a preparation of sumac to (an object#Noun|object), for example, to a piece of leather to tan#Verb|tan it.