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

Though weed pollination depends on the amount of daylight, fall can still bring allergens like pollen from ragweed. —Mariyam Muhammad, The Enquirer, 16 Aug. 2024

The list of allergens that SLIT can help fix is much smaller—at the moment, only short ragweed pollen, grasses, and house dust mites—and only one of these at a time. —Kathleen Felton, SELF, 10 June 2024

Tree and grass pollen levels will be very high on Tuesday, along with moderate levels of ragweed pollen. —Hanh Truong, Sacramento Bee, 7 May 2024

Types of allergies: Nasal sprays can help with seasonal allergies to things like pollen, grass, or ragweed, perennial allergies to dust mites or pet dander, and non-allergic rhinitis. —Shannon Ullman, Health, 6 May 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