Pirate Cutlass
Cutlass was originally used by pirates and buccaneers(essentially another name for pirates). The word cutlass comes from a 17th-century English variation of coutelas, a 16th-century French word for a machete-like blade. The cutlass has a short curved blade and was historically favored by sailors because of its effectiveness as a fighting tool in close quarters. The short curved blade allowed for quick slashing movements useful in a melee style battle. Even today sailing vessels have limited space but even more so in the 16th century. Someone wielding a long bladed weapon would have been at a distinct disadvantage as compared to a much more maneuverable short blade.
See Strongblade's Pirate Cutlass