kodachi
The kodachi (小太刀; "short sword") is a traditional Japanese sword that is similar in length to a wakizashi, but is intended to be wielded as a primary weapon rather a companion to a katana. A kodachi typically has a slightly more curved blade and a longer grip (for two-handed use) compared to the wakizashi. The typical purpose of the kodachi was to allow those not of the samurai class (and thus forbidden to carry a katana) to be armed.
See also:
This tag implicates short_sword (learn more).