The name sackbutt (perhaps an Anglification of some Spanish or French words, referring to the pushing and pulling movement of the sliding mechanism) might be regarded as an alternative name for the more modern name trombone.
This kind of bugle or trumpet instrument uses a sliding mechanism to change the length of the pipe instead of keys, and dates from the Renaissance and Baroque eras.
Source: http://www.miayf.org/brasswind/sackbut/
Source: http://en.wikipedia.org/wiki/File:Sackbutt.jpg
The "sackbutt" of some sorts, that is as a type of bugle or trumpet using a slider to change pitch, probably originated some time in the early 1400s. In Italy it was called the tromba, which means trumpet, from which the modern name trombone is derived.