guinea (n.)

former British coin, 1660s, from Guinea, because the coins were first minted for British trade with Guinea (but soon in domestic use) and with gold from Africa. The original guinea was in use from 1663 to 1813.

region along the west coast of Africa, presumably from an African word (perhaps Tuareg aginaw "black people"). As a derogatory term for "an Italian" (1896) it is from Guinea Negro (1740s) "black person, person of mixed ancestry;" applied to Italians probably because of their dark complexions relative to northern Europeans, and after 1911 it was occasionally applied to Hispanics and Pacific Islanders as well. New Guinea was so named 1546 by Spanish explorer Inigo Ortiz de Retes in reference to the natives' dark skin and tightly curled hair. The Guinea hen (1570s) is a domestic fowl imported from there. Related: Guinean.