poison oak
noun
either of two shrubs, Rhus toxicodendron, of the eastern U.S., or R. diversiloba, of the Pacific coast of North America, resembling poison ivy and causing severe dermatitis when touched by persons sensitive to them.
Also called
poison ivy.
Origin of poison oak
An Americanism dating back to 1735–45
Words nearby poison oak
Example sentences from the Web for poison oak
British Dictionary definitions for poison oak
poison oak
noun
either of two North American anacardiaceous shrubs, Rhus toxicodendron or R. diversiloba, that are related to the poison ivy and cause a similar rash
See also sumach (def. 1)
(not in technical use) another name for poison ivy
Medical definitions for poison oak
poison oak
n.
Either of two shrubs, Rhus toxicodendron of the southeast United States or R. diversiloba of western North America, related to poison ivy and causing a rash on contact.
poison ivy