arquebuse

The arquebus (sometimes spelled harquebus, harkbus or hackbut; from Dutch haakbus, meaning "hook gun") was a primitive firearm used in the 15th to 17th centuries. Like its successor, the musket, it was a smoothbore firearm, although somewhat smaller than its predecessors, which made it easier to carry. It was a forerunner of the rifle and other longarm firearms.
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n. arquebus

(n.)
A sort of hand gun or firearm a contrivance answering to a trigger, by which the burning match was applied. The musket was a later invention.