poison oak


noun
  1. either of two shrubs, Rhus toxicodendron, of the eastern United States, or R. diversiloba, of the Pacific coast of North America, resembling poison ivy and causing severe dermatitis when touched by persons sensitive to them.

Origin of poison oak

1
An Americanism dating back to 1735–45

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How to use poison oak in a sentence

British Dictionary definitions for poison oak

poison oak

noun
  1. 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)

  2. (not in technical use) another name for poison ivy

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