Yan Yue Dao (偃月刀)

Drawing of a Yan Yue Dao, from 'Chou Hai Tu Bian (《籌海圖編》)'.

Yan Yue Dao (偃月刀, lit. 'Reclining moon glaive'), also known as Chun Qiu Da Dao (春秋大刀, lit. 'Spring and autumn great glaive') or simply Da Dao (大刀, lit. 'Great glaive'), was arguably the most iconic Chinese polearm. Due of its association with legendary Chinese commander/war deity Guan Yu (關羽), it is also known as Guan Dao (關刀).

Yan Yue Dao was very similar to Zhan Ma Dao (斬馬刀) and could be used in pretty much the same manner (as both are glaive-like polearms). It had a trailing point blade with a sharpened protrusion on the back of its blade that aided parrying, and always mounted a three-sided butt spike, distinguishing it from other Chinese glaives.

While some Yan Yue Dao were extremely heavy and considered impractical for the battlefield, lightweight version intended as practical weapon did exist.