urushiol

American  

[oo-roo-shee-awl, -ol] / ʊˈru ʃiˌɔl, -ˌɒl /

noun

1. a toxic, liquid, catechol derivative, the active irritant principle in several species of the plant genus Rhus, as in poison ivy.

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urushiol British  

/ uːˈruː-, ˈuːrʊʃɪˌɒl /

noun

1. a poisonous pale yellow liquid occurring in poison ivy and the lacquer tree

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urushiol Scientific  

/ -ro̅o̅′shē-ôl′,-ōl′ /

1. A toxic substance present in the resin or on the surface of plants of the genus Rhus (syn. Toxicodendron). Urushiol is a mixture of several derivatives of catechol and is the irritating substance in poison ivy.

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Etymology

Origin of urushiol

1910–15; < Japanese urushi lacquer + -ol ¹

Example Sentences

The oily substance it contains, urushiol, tends to cause more intense reactions over time and it affects up to 90 percent of people.

From National Geographic • Apr. 18, 2023

Among recent discoveries: surprising pathways that cause the itchy rash, new targets for treatment and—be still, my heart—a vaccine in development that aims to prevent the urushiol reaction.

From Scientific American • Sep. 20, 2021

The protector cells defend your body against the intruder by attacking the urushiol in the skin.

From Washington Post • Sep. 10, 2021

Mohan did not find that the temperature of the soil had an effect on the potency of plants' urushiol, a small silver lining.

From Salon • Jul. 29, 2021

The Forest Service found that between 70 and 85 percent of the population is sensitive to urushiol, and people are likely to become more allergic to it every time they are exposed.

From Salon • Jul. 29, 2021