'Harpoon gun' definitions:

Definition of 'harpoon gun'

From: WordNet
noun
A cannon or similar gun that fires harpoons

Definition of 'Harpoon gun'

From: GCIDE
  • Harpoon \Har*poon"\ (h[aum]r*p[=oo]n"), n. [F. harpon, LL. harpo, perh. of Ger. origin, fr. the harp; cf. F. harper to take and grasp strongly, harpe a dog's claw, harpin boathook (the sense of hook coming from the shape of the harp); but cf. also Gr. "a`rph the kite, sickle, and E. harpy. Cf. Harp.] A spear or javelin used to strike and kill large fish, as whales; a harping iron. It consists of a long shank, with a broad, flat, triangular head, sharpened at both edges, and is thrown by hand, or discharged from a gun. [1913 Webster]
  • Harpoon fork, a kind of hayfork, consisting of a bar with hinged barbs at one end and a loop for a rope at the other end, used for lifting hay from the load by horse power.
  • Harpoon gun, a gun used in the whale fishery for shooting the harpoon into a whale. [1913 Webster]