Ragweed - Definition
ragweed
n 1: widespread European weed having yellow daisylike flowers;
sometimes an obnoxious weed and toxic to cattle if consumed
in quantity [syn: ragwort, tansy ragwort, ragweed,
benweed, Senecio jacobaea]
2: any of numerous chiefly North American weedy plants
constituting the genus Ambrosia that produce highly
allergenic pollen responsible for much hay fever and asthma
[syn: ragweed, ambrosia, bitterweed]