any of various twining vines, esp. any of certain vines (genus Convolvulus) of the morning-glory family
See bindweed in American Heritage Dictionary 4
noun
Any of various trailing or twining, often weedy plants of the genera Calystegia and Convolvulus, having white, pink, or purple bell-shaped or funnel-shaped flowers.
Any of various similar trailing or twining plants, such as the black bindweed.