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

Allergy season typically starts in early March with tree pollen and continues through the spring and summer with grass pollen, and then into the fall with ragweed pollen. —Stephen Underwood, Hartford Courant, 4 Apr. 2025

Common types include seasonal allergies (e.g., pollen, ragweed) and environmental allergies (e.g., mold, dust, pet dander). —Lindsay Curtis, Health, 25 Apr. 2025

As a result, grass pollen increasingly overlaps with the ragweed pollen season, which itself has been extended by more than three weeks in some parts of the country since 1995. —Umair Irfan, Wired News, 5 Apr. 2025

While anywhere that there is plant growth is susceptible to various pollens and ragweed, some cities and regions in the United States seem notoriously bad for allergy sufferers. —Laura Baisas, Popular Science, 10 Apr. 2025

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