poison oak

(noun) dermatitis resulting from contact with a poison oak plant. Synonyms: poison oak.

(noun) 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. Synonyms: poison ivy, markweed, poison mercury, poison oak, Toxicodendron radicans, Rhus radicans.