In Roman religion and mythology: the god of the sea, corresponding to the Greek Poseidon. Also in allusive use, or as a personification of the sea.

With the. (A name for) Poseidon or Neptune, the god of earthquakes.

He who bears a trident; the wielder of the trident; Neptune.

One who encircles or surrounds; circler of the earth, transl. of Greek γαιήοχος.

a person, god, fish, etc., regarded as presiding over the water as or like a monarch; spec. (a) the god Neptune; (b) a large or powerful fish.