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)
Examples of urushiol in a Sentence
Recent Examples on the Web
Oftentimes, so is the tough shell that surrounds the nut, which contains a toxic resin called urushiol, which is also found in poison ivy.
—
New Atlas, 26 Mar. 2025
Keep in mind that, like poison ivy, dead poison oak stems and leaves still contain urushiol and can cause a rash even after being dead for several years.
—Andy Wilcox, Better Homes & Gardens, 19 Sep. 2024
Dead poison ivy vines and leaves still contain urushiol and can cause a rash even after being dead for several years.
—Andy Wilcox, Better Homes & Gardens, 25 July 2024
If the sap from this plant comes in contact with your skin, a chemical called urushiol in the sap can cause unpleasant rashes and blisters that can last for weeks.
—Andy Wilcox, Better Homes & Gardens, 25 July 2024
Because urushiol can cling to clothing and shoes, take precautions not to transfer the oily substance to yourself or other items when undressing.
—Christopher Bergland, Verywell Health, 3 July 2024
For example, mango skin contains urushiol, the same compound found in poison ivy, which can trigger allergic reactions in people who are susceptible.
—Nick Blackmer, Verywell Health, 12 June 2024
This is because every part of the plant contains and emits a resin known as urushiol.
—Southern Living Editors, Southern Living, 29 July 2023
Mangos, cashews and pistachios can contain small amounts of urushiol.
—Scientific American, 1 Jan. 2022
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New Atlas, 26 Mar. 2025
Keep in mind that, like poison ivy, dead poison oak stems and leaves still contain urushiol and can cause a rash even after being dead for several years.
—Andy Wilcox, Better Homes & Gardens, 19 Sep. 2024
Dead poison ivy vines and leaves still contain urushiol and can cause a rash even after being dead for several years.
—Andy Wilcox, Better Homes & Gardens, 25 July 2024
If the sap from this plant comes in contact with your skin, a chemical called urushiol in the sap can cause unpleasant rashes and blisters that can last for weeks.
—Andy Wilcox, Better Homes & Gardens, 25 July 2024
Because urushiol can cling to clothing and shoes, take precautions not to transfer the oily substance to yourself or other items when undressing.
—Christopher Bergland, Verywell Health, 3 July 2024
For example, mango skin contains urushiol, the same compound found in poison ivy, which can trigger allergic reactions in people who are susceptible.
—Nick Blackmer, Verywell Health, 12 June 2024
This is because every part of the plant contains and emits a resin known as urushiol.
—Southern Living Editors, Southern Living, 29 July 2023
Mangos, cashews and pistachios can contain small amounts of urushiol.
—Scientific American, 1 Jan. 2022
Cite this Entry
“Urushiol.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/urushiol. Accessed 29 May. 2025.
Copy CitationMedical Definition
urushiol
noun
uru·shi·ol
(y)u̇-ˈrü-shē-ˌȯl
-ˌōl
-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
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