A gladius was a short sword used by the Roman Empire and by Magna Romans.
In the 2260s, Magna Roman police and guards were all armed with gladdii and gladiators also used them in combat. (TOS episode: "Bread and Circuses")
In 2268, gladii were among the weapons that (*) created when the crews of the USS Enterprise and IKS Klolode fought each other. (TOS episode: "Day of the Dove")
In 2364, Magna Romans aboard the USS Centurion trained on the holodeck using gladii and other ancient weapons. (TNG novel: The Captains' Honor)