Definition of: butterfly weed

1. A bushy species of milkweed (Asclepias tuberosa), common in the United States and Canada, and conspicuous in midsummer by its large masses of orange-red flowers: also called orange or vermilion milkweed.
2. A native North American plant (Gaura coccinea) of the primrose family, with small pink, red, or white flowers.
3. Pleurisy root.
BUTTERFLY WEED (def. 1)