ˈ ̷ ̷ˌ ̷ ̷ noun
Etymology: rag (II) + weed; from the ragged shape of the leaves
1. : tansy ragwort
2. : any of various chiefly No. American weedy herbaceous plants that constitute the genus Ambrosia and produce 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 No. America and is introduced elsewhere by accident
b. : great ragweed
c. : an annual to perennial highly variable weed ( A. psilostachya ) chiefly of dry barren lands of the southwestern United States and Mexico
3. : franseria 2