yam1 /yam, jæm 
/ ▸ noun 1 the edible starchy tuber of a climbing plant that is widely grown in tropical and subtropical countries. 2 the cultivated plant that yields the yam. Genus
Dioscorea, family
Dioscoreaceae: many species
. 3 North American a sweet potato. – ORIGIN late 16th century : from Portuguese inhame or obsolete Spanish iñame, probably of West African origin.
EnglishOxford New American Dictionary
