ragweed

noun

rag·​weed ˈrag-ˌwēd 

: any of various chiefly North American weedy composite herbs (genus Ambrosia) that produce highly allergenic pollen

Illustration of ragweed

Examples of ragweed in a Sentence

Recent Examples on the Web

Common types are crabgrass, goosegrass, giant foxtail, smooth pigweed, common lambs quarters, purslane, galinsoga, common ragweed, and tall morning glory. —Mary Marlowe Leverette, Southern Living, 14 Mar. 2026

Weed pollen — especially ragweed — is another major allergy trigger, affecting about one in seven people, the foundation said. —Sacbee.com, 13 Mar. 2026

Allergy season typically starts in early March with tree pollen, continues through the spring and summer with grass pollen and ends in the fall with ragweed pollen. —Stephen Underwood, Hartford Courant, 12 Mar. 2026

This North American native beauty is too often mistaken for ragweed and incorrectly deemed a nuisance. —Carl R. Gold, Baltimore Sun, 7 Mar. 2026

Word History

First Known Use

1790, in the meaning defined above

Rhymes for ragweed

• accede
• agreed
• airspeed
• alkyd
• bindweed
• chickweed
• concede
• decreed
• duckweed
• exceed
• flaxseed
• impede

Kids Definition

ragweed

noun

rag·​weed ˈrag-ˌwēd 

: any of various chiefly North American weedy herbs related to the daisies and producing pollen irritating to the eyes and noses of some persons

Medical Definition

ragweed

noun

rag·​weed ˈrag-ˌwēd 

: any of various chiefly North American weedy herbaceous plants comprising the genus Ambrosia and producing highly allergenic pollen responsible for much hay fever and asthma: as

a

: an annual weed (A. artemisiifolia) with finely divided foliage that is common on open or cultivated ground in much of North America

b

: a coarse annual (A. trifida) with some or all of the leaves usually deeply and palmately 3-cleft or 5-cleft

called also great ragweed