n 1  cap  :  a genus of shrubs and trees of the cashew family (Anacardiaceae) that are native to temperate and warm regions, have compound trifoliolate or pinnate leaves, and include some (as poison ivy, poison oak, and poison sumac) producing irritating oils that cause dermatitis - see SUMAC, TOXICODENDRON   2  pl  rhuses  or  rhus  :  any shrub or tree of the genus Rhus .
 
 
 
Published under license with Merriam-Webster, Incorporated.  © 1997-2024.