Meaning

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

verb spear with a harpoon

originFrom Old French harpon, from Latin harpaga, a variant of Latin harpagō, from Ancient Greek ἁρπάγη (harpágē, “hook”), from ἁρπάζω (harpázō, “to snatch away, to carry off, to seize, to captivate”). Sense and spelling perhaps influenced by Dutch harpoen (“harpoon”). Doublet of harpagon.

Etymology from Wiktionary, CC BY-SA 3.0