slang, "gentile, non-Jew," pejorative, 1920, from Yiddish, where it is back slang, a reversed and altered form of goy.
Entries linking to yok
goy n.
"a gentile, a non-Jew" (plural goyim), 1835, from Hebrew goy "people, nation;" in Mishnaic and Modern Hebrew, also "gentile" (compare gentile). The fem. form of the Hebrew word entered French as gouge "a wench" (15c.).