Old English tusc, also transposed as tux, "long, pointed tooth protruding from the mouth of an animal," cognate with Old Frisian tusk, probably from Proto-Germanic *tunthsk- (cognates: Gothic tunþus "tooth"), from an extended form of PIE *dent-, the root of tooth. But "there are no certain cognates outside of the Anglo-Frisian area" [OED].[tusk etymology, tusk origin, 英语词源]