What is "guandao"

n. a Chinese polearm with the blade mounted on top of the pole (as opposed to on the side like most European polearms).

A guandao is a type of Chinese pole weapon that is used in some forms of Chinese martial arts. In Chinese, it is properly called a yanyuedao (偃月刀; lit. "reclining moon blade"), the name under which it always appears in texts from the Song to Qing dynasties such as the Wujing Zongyao and Huangchao Liqi Tushi. It is comparable to a European fauchard or glaive and consists of a heavy blade with a spike at the back and sometimes also a notch at the spike's upper base that can catch an opponent's weapon. In addition there are often irregular serrations that lead the back edge of the blade to the spike. The blade is mounted atop a 1.5 m to 1.8 m (5–6 foot) long wooden or metal pole with a pointed metal counter weight used to balance the heavy blade and for striking on the opposite end.

On modern versions, a red sash or tassel is attached at the joint of the pole and blade. Variations include having rings along the length of the straight back edge as found in the nine-ring guandao, having the tip curl into a rounded spiral as in the elephant guandao, or featuring a more ornate design as exemplified by the dragon head guandao. However, apart from the "elephant guandao" none of these variations seem to have historical ground.

It has also been called a "big knife" by some western sources.