| 1. | 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. |
| 2. | 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. |
| 3. | the wood of these trees. |

sumac su·mac or su·mach (s&oomacr;'māk, sh&oomacr;'-)
n.
Any of various shrubs or small trees of the genus Rhus, having compound leaves, clusters of small greenish flowers, and usually red, hairy fruit. Some species, such as the poison ivy and poison oak, cause an acute itching rash on contact.