probably borrowed from a Twi word, or from a related loanword in another West African language
Note:
G. A. Christaller, Dictionary of the Asante and Fante Language Called Tshi (Twi), 2nd edition (Basel, 1933), has the following entries: àŋkyẽ, áŋkyẽ "a kind of wild cashew tree; its fruits (they are eaten by the Krobos)"; akyẽ́à "cashew nut; Gã: atĩa." It is uncertain if Christaller's "wild cashew tree" should be equated with Blighia sapida, which does not have the cashew's distinctive drupe and accessory fruit. The etymology "Kru ā-kee," which appears in several dictionaries (as Cassidy and Le Page, Dictionary of Jamaican English, 2nd edition, Cambridge, 1980) is based ultimately on Merriam-Webster's second unabridged dictionary (Webster's New International of 1934). The Merriam-Webster files contain an unattributed note that is apparently the source of this etymology: "This seems to be the Kru word 'ā-kee' which is used for a tree yielding an excess of sap but its exact botanical name is not certain." Lorenzo Turner, the African etymologist for Merriam-Webster's 3rd unabridged dictionary (1961), retained the "Kru" etymology but noted that he could not confirm it. As Kru is now understood to be a family of more than twenty languages, its application here is not known.