Poison ivy Meaning, Definition & Usage

  1. noun dermatitis resulting from contact with the poison ivy plant
    • my poison ivy is drying up
  2. 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
    poison mercury; poison oak; Toxicodendron radicans; markweed; Rhus radicans.

WordNet

Definitions
  1. (Bot.), an American woody creeper (Rhus Toxicodendron), with trifoliate leaves, and greenish-white berries. It is exceedingly poisonous to the touch for most persons.
Definitions
  1. (Bot.), a poisonous climbing plant (Rhus Toxicodendron) of North America. It is common on stone walls and on the trunks of trees, and has trifoliate, rhombic-ovate, variously notched leaves. Many people are poisoned by it, if they touch the leaves. See Poison sumac. Called also poison oak, and mercury.

Webster 1913