noun. A name given to American species of ragweed, Ambrosia artemisiæfolia and A. trifida.

noun. A species of Ambrosia (Ambrosia artemisiæfolia); Roman worm wood.

noun. Any plant in the genus Ambrosia, especially Ambrosia artemisiifolia.

noun. The plant Artemisia trifida.

noun. The plant Helenium amarum.

noun. widespread European weed with spiny tongue-shaped leaves and yellow flowers; naturalized in United States

noun. any of numerous chiefly North American weedy plants constituting the genus Ambrosia that produce highly allergenic pollen responsible for much hay fever and asthma

"hundreds of thousands of wisconsin union membership residents would be happy to donate. where would you like the checks sent? bitterweed wrote:"

weed