Synonyms for Potato Bean (same or very similar meaning)
WordNet sense 1 (twining plant of Amazon basin having large edible roots):
yam bean, Pachyrhizus tuberosusWordNet sense 2 (a North American vine with fragrant blossoms and edible tubers; important food crop of Native Americans):
groundnut, Indian potato, Apios americana, Apios tuberosa, groundnut vine, wild beanFrom the ODE community, based on WordNetadd/edit