A tachi is a type of Japanese sword. Tachi may also refer to: Tachi (surname), a Japanese surname A Japanese term for Karate stances, varying body positions to attack and defend. A suffix used in the Japanese language to indicate that a word refers to a group. See the article on Japanese grammar. A tribe of Native American Indians in California - see Yokuts and Santa Rosa Rancheria TOM'S (Tachi Oiwa Motor Sports), TOM'S Co., Ltd (株式会社トムス, Kabushiki-gaisha Tomusu) is a factory supported racing team and tuner of Toyota and Lexus vehicles. Alberto Rodríguez, Spanish footballer born 1997 who goes by the nickname "Tachi"