urushiol

noun

uru·​shi·​ol yu̇-ˈrü-shē-ˌȯl 

u̇-ˈrü-,

-ˌōl 

: a mixture of catechol derivatives with saturated or unsaturated side chains of 15 or 17 carbon atoms that is an oily toxic irritant substance present in poison ivy and some related plants (such as poison oak and poison sumac)

Example Sentences

Recent Examples on the Web

Poison Sumac Poison sumac is similar to poison ivy and poison oak in terms of having the poisonous oily resin called urushiol. —Chandra Fleming, Detroit Free Press, 15 Mar. 2023

The urushiol in mangos can also cause an allergic reaction when consumed. —Emilie Le Beau Lucchesi, Discover Magazine, 1 Sep. 2022

Higher urushiol concentrations could mean that more and more people become affected by poison ivy. —Karl Schneider, The Indianapolis Star, 5 Sep. 2022

Poison ivy, oak and sumac contain a substance called urushiol, which is a clear liquid compound found all parts of the plant. —Tim Macwelch, Outdoor Life, 13 Aug. 2019

All parts of the plant contain an oily chemical called urushiol that, in most people, causes a severe allergic reaction on contact. —Beth Botts, chicagotribune.com, 28 June 2017

Remember that urushiol can cling to surfaces and be transferred to skin. —Beth Botts, chicagotribune.com, 28 June 2017

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Word History

Etymology

International Scientific Vocabulary, from Japanese urushi lacquer + International Scientific Vocabulary -ol entry 1

First Known Use

1908, in the meaning defined above

Medical Definition

urushiol

noun

uru·​shi·​ol (y)u̇-ˈrü-shē-ˌȯl  -ˌōl 

: a mixture of pyrocatechol derivatives with saturated or unsaturated side chains of 15 or 17 carbon atoms that is an oily toxic irritant principle present in poison ivy and some related plants of the genus Rhus