400 year-old Dandao sword
Dao is a category of single-edge Chinese swords primarily used for slashing and chopping (sabres), often called a broadsword in English translation because some varieties have wide blades. In China, the dao is known as one of the four major weapons, along with the gun (staff), qiang (spear), and the jian (sword), and referred to as the “General of All Weapons”.
Dao is actually a generic word used to denote any member of a family of single-edged, broad-bladed cutting or slicing tools, but in common, everyday usage means knife. The weapon, also known as dan dao (single knife) when just one is used, is thereby thought to be an adaptation of the kitchen knives common to Chinese cuisine. [Via: wikipedia]