harpoon vs fishgig

harpoon and fishgig both are nouns.

Word	Noun	Adjective	Verb	Adverb
harpoon	Yes	No	Yes	No
fishgig	Yes	No	No	No

As nouns, fishgig is a hypernym of harpoon; that is, fishgig is a word with a broader meaning than harpoon:

harpoon: a spear with a shaft and barbed point for throwing; used for catching large fish or whales; a strong line is attached to it
fishgig: an implement with a shaft and barbed point used for catching fish

Other hypernyms of harpoon include fizgig, gig, lance, spear.

harpoon (noun)	fishgig (noun)
a spear with a shaft and barbed point for throwing; used for catching large fish or whales; a strong line is attached to it	an implement with a shaft and barbed point used for catching fish

harpoon (verb)	fishgig (verb)
spear with a harpoon