poison ivy

noun

1

a

: a climbing plant (Toxicodendron radicans synonym Rhus radicans) of the cashew family that is especially common in the eastern and central U.S., that has ternate leaves, greenish flowers, and white berries, and that produces an irritating oil causing a usually intensely itching skin rash

b

: any of several plants closely related to poison ivy

2

: a skin rash caused by poison ivy

Illustration of poison ivy

• poison ivy 1a

Examples of poison ivy in a Sentence

I got poison ivy all over my arm.

Recent Examples on the Web

Wash any fabric items that have been in contact with someone suffering from lice, poison ivy or oak, pinkeye, ringworm, etc. frequently in hot water to prevent them from spreading or causing reinfection. —Jolie Kerr, Better Homes & Gardens, 21 Oct. 2024

Their job is to clear about 5 acres of overgrown vegetation including weeds, poison ivy, poison oak and other problematic vegetation. —Kara King, Austin American-Statesman, 18 July 2024

The urushiol oil that causes poison sumac rash is also found in poison ivy and poison oak. —Christopher Bergland, Verywell Health, 3 July 2024

And no one, regardless of your experience level, likes to accidentally sit on poison ivy. —New Atlas, 25 Oct. 2024

Word History

First Known Use

1782, in the meaning defined at sense 1a

Kids Definition

poison ivy

noun

1

: a usually climbing plant that is related to the sumacs, has leaves usually with three leaflets, greenish flowers, white berries, and leaves and stems that when bruised and touched may cause an itching rash on the skin

2

: a skin rash caused by poison ivy

Medical Definition

poison ivy

noun

-ˈī-vē 

1

a

: a climbing plant of the genus Rhus (R. radicans synonym Toxicodendron radicans) that is especially common in the eastern and central United States, that has leaves in groups of three, greenish flowers, and white berries, and that produces an acutely irritating oil causing a usually intensely itching skin rash

b

: any of several plants closely related to poison ivy

especially : poison oak sense 1b

2

: a skin rash produced by poison ivy