Various gladii
On the planet 892-IV, the gladius was used by the police and guards as a side weapon. It was also used in gladiatorial combat and executions. Captain James T. Kirk was almost killed by one. (TOS: "Bread and Circuses")
On the transport asteroid Yonada, the Fabrini soldiers were armed with swords that resembled imitation gladii. (TOS: "For the World is Hollow and I Have Touched the Sky")
Later in 2268 when the Beta XII-A entity altered the USS Enterprise, and gave everyone primitive weapons, various versions of gladii were created. Pavel Chekov was given a proper one of these, and later, Kirk and Kang faced each other with "imitation" ones. (TOS: "Day of the Dove")