Yam
late 16th century: from Portuguese inhame or obsolete Spanish iñame, probably of West African origin.
wiktionary
From Portuguese inhame and Spanish ñame, likely from Wolof ñàmbi(“cassava”) or a related word. The term was spelled yam as early as 1657. Doublet of name.
Alternative form of hjem. Likely caused by Old Norse influence from Old Norse heim(“home, homewards”), the accusative form of heimr(“abode, world, land”), from Proto-Germanic *haimaz. More at home.
yam
etymonline
yam (n.)
1580s, igname (current form by 1690s), from Portuguese inhame or Spanish igname, from a West African language (compare Fulani nyami "to eat;" Twi anyinam "species of yam"); the word in American and Jamaican English probably is directly from West African sources. The Malay name is ubi, whence German öbiswurzel.
