The bilbo is a type of 16th century, cut-and-thrust sword or small rapier formerly popular in America.  They have well-tempered and flexible blades and were very popular aboard ships, where they were used in a similar role to that of the cutlass. The term probably comes from the Basque city of Bilbao, where a significant number of them were made and exported to the New World. These swords were also sold to merchants of every European nation, including England.
Bilbo (Basque: Labana Bizkaitarra, Spanish: daga vizcaína (Biscayne dagger)) is an English catch-all word used to very generally refer to the "utilitarian" cup-hilt swords, often found all over America. They usually had a wide, relatively short sturdy and well tempered blade, very practical and comparatively unadorned. The grip was often covered with wire, rather than plain wood.