A chokutō is a type of sword that originated in ancient China and was later introduced to Japan. It is characterized by its straight blade, unlike the curved blades of the later Japanese swords such as the tachi and katana. The term "chokutō" translates to "straight sword" in Japanese.

In Japan, the chokutō is primarily associated with swords from the Kofun period (around 3rd to 6th century CE) and is considered a precursor to the curved swords that followed. These early Japanese chokutō swords were influenced by Chinese sword designs and were typically made of iron or low-carbon steel.

The length of a chokutō can vary, but they are generally around 60 to 80 centimeters (approximately 23 to 31 inches) in blade length. The blade was often single-edged, with a sharp cutting edge and a straight back.

It's important to note that the term "chokutō" can sometimes be used more broadly to refer to any straight sword in Japanese sword terminology. However, in the specific historical context of ancient Japan, the chokutō is associated with early straight swords that predate the curved blades commonly associated with Japanese swords.