The term "tsurugi" (剣) refers to a type of bladed weapon that was once commonly used in Japan but is now mainly associated with ancient historical times and mythology.
It is a double-edged sword, meaning that it has cutting edges on both sides of the blade, unlike tachi, katana, wakizashi, or nodachi, which are single-edged swords with the cutting edge on one side of the blade.
Tsurugi swords were typically forged during the Bronze Age in Japan. The term is used to describe short swords with straight blades, as well as various similar weapons, such as the Chinese jian. The most famous example of a tsurugi is the mythical sword Kusanagi-no-Tsurugi, one of the three sacred treasures of Japan.