The wakizashi - meaning "side inserted sword" is one of the traditionally made Japanese swords worn by the samurai class in feudal Japan.
The wakizashi being worn together with the katana was the official sign that the wearer was a samurai or swordsman of feudal Japan. When worn together the pair of swords were called daishō, which translates literally as "big-little".
The wakizashi was one of several short swords available for use by samurai including the tantō.
While the wearing of katana was limited to the samurai class, wakizashi of legal length (ko-wakizashi) could be carried by the chonin class which included merchants. This was common when traveling due to the risk of encountering bandits. Wakizashi were worn on the left side, secured to the waist sash.