Source : Webster's Revised Unabridged Dictionary (1913)
Ragweed \Rag"weed\, n. (Bot.)
A common American composite weed ({Ambrosia
artemisi[ae]folia}) with finely divided leaves; hogweed.
{Great ragweed}, a coarse American herb ({Ambrosia trifida}),
with rough three-lobed opposite leaves.
Source : WordNet®
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}, {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: {ambrosia}, {bitterweed}]