Semispathae

[Agraes]

I'm not considering the later "germanic" sax, which is seen mostly from the 6th century onwards but earlier sax and lattes of (pick up your own theory) steppic, danubian, eastern roman or sassanian origin.
Along with new fashions brought west by the Huns and Goths this kind of weapon seems to have become valued by the germanic elites but it seems possible to me it was also used by the 5th century western roman army. See Graham Sumner's illustration of one of Aetius' hunnic bodyguards for exemple in Osprey Roman Military Clothing 3. Same kind of weaponry also depicted in the second volume of D'Amato book about centurions.