Language: Mandarin Chinese
Dāo (刀) in Chinese is used to describe a wide variety of single-edged tools and weapons. A dāo can be a knife, a saber, a backsword, a falchion, a pole-arm, and so on.
In martial arts and collector's circles, dāo (刀) is usually used to describe the standard Chinese saber. It is, of course, preferable to use more specific terms in that case, like pèidāo or niúwěidāo.
A pèidāo or "waist-worn saber" which could have any type of blade form.
A classic niúwěidāo.
A shūndāo, which is a small utility knife used primarily to cut meat.
The diagram below shows a number of types of dāo (刀) in use by the Green Standard Army in the 18th century. Although this is just a fraction of the items that are categorized as dāo, it gives an indication of the broad variety of implements categorized as such.