The word "katana" refers to a traditional Japanese sword with a curved blade, which has been used for centuries. There are other names for this sword that are used in different parts of the world. Some examples include the "samurai sword," which is a more commonly-known term in Western countries; the "uchigatana," which refers to a shorter type of katana that has a straighter blade; and the "tachi," which is a similar sword that was worn with the blade facing downwards. Other related terms include the "wakizashi," which is a shorter sword used as a companion to the katana, and the "naginata," which is a polearm with a curved blade similar to the katana.