Definition of poison oak in English English dictionary
a North American plant with leaves similar to an oak tree's, that makes your skin hurt and itch if you touch it. Species of poison ivy (Toxicodendron diversilobum) native to western North America and classified in the sumac (or cashew) family. Like many other lobe-leafed plants commonly called oak, poison oak is not an oak tree (genus Quercus)
climbing plant common in eastern and central United States with ternate leaves and greenish flowers followed by white berries; yields an irritating oil that causes a rash on contact