Definition of sumac
- a shrub or small tree of the cashew family, with compound leaves, fruits in conical clusters, and bright autumn colors.
- Genera Rhus and Cotinus, family Anacardiaceae: several species, including the North American staghorn sumac (R. typhina), with densely clustered reddish hairy fruits, and poison sumac (R. vernix), with loosely clustered greenish-white fruits. Touching any part of the poison sumac can cause severe dermatitis
Middle English (denoting the dried and ground leaves of R. coriaria used in tanning and dyeing): from Old French sumac or medieval Latin sumac(h), from Arabic summāḳ