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

Growing up in the South with pollen and ragweed didn't make matters any better. —Gaylyn Henderson, Mph, Health, 25 Jan. 2025

The most common culprit for fall allergies is a plant called ragweed, the CDC says, which can release 1 billion grains of pollen per plant. —Alexandra Banner, CNN, 22 Oct. 2024

September and October are known for ragweed season and pollen from some fall trees. —Nicole Villalpando, Austin American-Statesman, 5 Dec. 2024

Pollen counts have been high in Houston, largely due to ragweed season. —Shafaq Patel, Axios, 18 Sep. 2024

Word History

First Known Use

1790, in the meaning defined above

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