sumac

Any of various shrubs or small trees of the genus Rhus and certain other genera in Anacardiaceae.

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

particularly, one of species Rhus coriaria (tanner's sumac)

Dried and chopped-up leaves and stems of a plant of the genus Rhus, particularly tanner's sumac (see sense 1), used for dyeing and tanning leather or for medicinal purposes.

To apply a preparation of sumac to (an object), for example, to a piece of leather to tan it.