The Collaborative International Dictionary
Potgun
Potgun \Pot"gun`\, n.
A pot-shaped cannon; a mortar. [Obs.] ``Twelve potguns of brass.''
--Hakluyt.A popgun. [Obs.]
--Swift.
Wiktionary
potgun
n. 1 (context obsolete English) A pot-shaped cannon; a mortar. 2 (context obsolete English) A pop gun.