A tsurugi (剣), yamatozurugi (倭剣) or nihonken (日本剣) is a Japanese sword. The word is used in the West to refer to a specific type of Japanese straight, double-edged sword used in antiquity (as opposed to curved, single-edged swords such as the katana).[1] In Japanese the term tsurugi or ken, ja:剣 is used as a term for all sorts of international long, double-edged swords.