| Noun | 1. | snail bean - perennial tropical American vine cultivated for its racemes of showy yellow and purple flowers having the corolla keel coiled like a snail shell; sometimes placed in genus Phaseolusgenus Vigna, Vigna - genus of vines or erect herbs having trifoliate leaves and yellowish or purplish flowers; of warm or tropical regions; most species often placed in genus Phaseolus | |