What does "hauberk" mean?

Hauberk: A coat of mail; especially, the long coat of mail of the European Middle Ages, as contrasted with the habergeon, which is shorter and sometimes sleeveless. By old writers it is often used synonymously with habergeon. See Habergeon. [Written variously hauberg, hauberque, hawberk, etc.] Chaucer. Helm, nor hawberk's twisted mail. Gray.