A hurlbat (or whirlbat, whorlbat) is a weapon of unclear original definition. Older reference works refer to it largely as a type of club, either held in the hand or possibly thrown. Modern usage appears to refer to a type of throwing-axe.
Modern usage
In modern usage, the term is used to refer to a throwing axe made of a single sheet of thin metal, sharpened to a point or blade on every auxiliary end.
References
Hurlbat Wikipedia(Text) CC BY-SA