Poseidon

American  

[poh-sahyd-n, puh-] / poʊˈsaɪd n, pə- /

noun

1. the ancient Greek god of the sea, with the power to cause earthquakes, identified by the Romans with Neptune.

2. Military. a 34-foot (10-meter), submarine-launched U.S. ballistic missile with up to 10 warheads and a range of 2,800 miles (4,502 km).

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Poseidon British  

/ pɒˈsaɪdən /

noun

1. Roman counterpart: Neptune.  Greek myth the god of the sea and of earthquakes; brother of Zeus, Hades, and Hera. He is generally depicted in art wielding a trident

2. a US submarine-launched ballistic missile

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Poseidon Cultural  

1. The Greek name for Neptune, the god in classical mythology who ruled the sea.

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Example Sentences

The U.S. brought in P-8 Poseidon “sub-hunter” aircraft and AC-130J gunships to help with the boarding operation of the ship south of Iceland, according to flight-tracking data and two U.S. officials.

From The Wall Street Journal • Jan. 7, 2026

Several other US aircraft have flown around the west coast of Scotland and south of Iceland, including a Poseidon reconnaissance plane and a Boeing KC-135T Stratotanker used for refuelling.

From BBC • Jan. 7, 2026

"Regarding the tests of Poseidon and Burevestnik, we hope that the information was conveyed correctly to President Trump," Kremlin spokesman Dmitry Peskov told journalists, referencing the names of Russian weapons.

From BBC • Nov. 3, 2025

Flights of B1 bombers and P-8 Poseidon spy planes have also been visible on plane tracking platforms.

From BBC • Oct. 23, 2025

At all events, whoever their mother was, their father was certainly Poseidon, although they went generally by the name of the Aloadae, the sons of Aloeus, their mother’s husband.

From "Mythology: Timeless Tales of Gods and Heroes" by Edith Hamilton