Definition of urushiol in English:

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Pronunciation: /(y)o͝oˈro͞oSHēˌôl/ Pronunciation: /-ˌōl/ Pronunciation: /-ˌäl/


An oily liquid that is the main constituent of Japanese lacquer and is responsible for the irritant properties of poison ivy and other plants. It consists of a mixture of catechol derivatives.
Example sentences
  • All parts of the poison ivy plant produce the oily irritating agent, urushiol.
  • Poison ivy, poison oak, and poison sumac all contain the same allergic irritant: urushiol.
  • Unfortunately, the study also found that carbon dioxide-enhanced poison ivy boasts a stronger strain of urushiol, which may prove even more poisonous to humans.


Early 20th century: from Japanese urushi 'Japanese lacquer' + -ol.

For editors and proofreaders

Syllabification: u·ru·shi·ol

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