n.
In Roman religion , the god of water.
Neptune was originally the god of fresh water, but by 399 BC he was identified with the Greek god Poseidon and thus became a deity of the sea. His female counterpart, Salacia, probably began as a goddess of spring water but was later equated with the Greek goddess Amphitrite. Neptune's festival (Neptunalia) took place in the heat of summer (July 23), when fresh water was scarcest. In art Neptune is often given Poseidon's attributes, the trident and dolphin.
Neptune holding his trident, classical sculpture; in the Lateran Museum, Rome
Alinari
Art Resource