What is the meaning of Spearfish?

Any of the genus Tetrapturus of marlins, a type of fish with the upper jaw elongated into a spearlike bill.

Any striped marlin (Kajikia audax)

Any quillback (Carpioides cyprinus

To try to catch a fish using a spear or spear gun.

To fish for spearfish by any method.

Source: wiktionary.org