Noun: ragweed 'rag,weed
- Any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma
"Ragweed pollen caused widespread allergies in late summer";
- ambrosia, bitterweed
Derived forms: ragweeds
Type of: weed
Part of: genus Ambrosia
Encyclopedia: Ragweed