poison oak

noun

1

: any of several plants related to poison ivy and producing an oil with similar irritating properties: such as

a

: a bushy plant (Toxicodendron diversilobum synonym Rhus diversiloba) of the Pacific coast

b

: a bushy plant (Toxicodendron pubescens synonym Rhus toxicodendron) chiefly of the southeastern U.S.

2

: poison ivy sense 1a

Examples of poison oak in a Sentence

Recent Examples on the Web

Hikers or runners should watch for poison oak, ticks, rattlesnakes or hazardous trail conditions. —Don Sweeney, Sacbee.com, 12 May 2026

Follow the same steps to permanently get rid of poison oak, the counterpart of poison ivy in the western part of the United States. —Patricia Shannon, Southern Living, 8 May 2026

Do keep an eye out for poison oak, which appears to be thriving in some creekside areas. —John Metcalfe, Mercury News, 4 May 2026

The trail does pass over a small flowing creek, but keep an eye out for poison oak near the water. —Maura Fox, San Diego Union-Tribune, 27 Mar. 2026

Word History

First Known Use

1739, in the meaning defined at sense 1

Rhymes for poison oak

• artichoke
• nanticoke
• womenfolk
• awoke
• baroque
• bespoke
• colloque
• convoke
• evoke
• invoke
• keystroke
• kinfolk

Kids Definition

poison oak

noun

: any of several shrubby plants related to poison ivy and causing a similar rash

Medical Definition

poison oak

noun

-ˈōk 

1

: any of several plants included in the genus Toxicodendron that produce an irritating oil like that of poison ivy:

a

: a bushy plant (T. diversilobum synonym R. diversiloba) of the Pacific coast

b

: a bushy plant (T. pubescens synonym R. toxicodendron) of the southeastern United States

2

: poison ivy sense 1a

3

: a skin rash produced by poison oak