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

Growing Conditions: Full sun and poor soil Size: 20 to 40 feet Zones: 5–9 06 of 10 Virginia Creeper Virginia creeper (Parthenocissus quinquefolia) is often confused with poison ivy (which is also a native plant), but this vine has five leaflets, not three. —Lauren Landers, Better Homes & Gardens, 23 Oct. 2024

Toby recounted a personal story of being able to quickly diagnose and treat a poison ivy rash on his daughter with an uploaded photo in a telemedicine consult, rather than spending the time and money to take her to an emergency department. —Bill Frist, Forbes, 8 Oct. 2024

Similar elastic bands at the ankles make for a secure fit, perfect for pulling over socks in areas where the poison ivy or poison oak hasn’t died back yet or to limit your chances of ticks. —Alice Bennett, Travel + Leisure, 28 Sep. 2024

Like its cousins, poison oak and poison ivy, poison sumac contains urushiol in every part of the plant, but is more toxic. —Leanne Potts, Better Homes & Gardens, 28 Sep. 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