submarine

American  

[suhb-muh-reen, suhb-muh-reen, suhb-muh-reen] / ˌsʌb məˈrin, ˈsʌb məˌrin, ˌsʌb məˈrin /

noun

submarines plural

1. a vessel that can be submerged and navigated under water, usually built for warfare and armed with torpedoes or guided missiles.

2. something situated or living under the surface of the sea, as a plant or animal.

3. Chiefly Northeastern and North Midland U.S. a hero sandwich.

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adjective

1. situated, occurring, operating, or living under the surface of the sea.

   a submarine mountain.

2. of, relating to, or carried on by a submarine or submarines.

   submarine warfare.

verb (used without object)

submarined, submarining

1. to participate in the operating of a submarine.

2. to move or slide under something.

3. Slang.

   1. to be thrown under the steering wheel of the vehicle one is driving during a frontal crash.

   2. to be thrown out of one's seat belt in such a crash.

verb (used with object)

submarined, submarining

1. to attack or sink by submarine.

submarine British  

/ ˈsʌbməˌriːn, ˌsʌbməˈriːn /

noun

1. Often shortened to: sub.  a vessel, esp one designed for warfare, capable of operating for protracted periods below the surface of the sea

2. (modifier)

   1. of or relating to a submarine

      a submarine captain

   2. occurring or situated below the surface of the sea

      a submarine cable

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Regionalisms

See hero sandwich.

Other Word Forms

Derived Forms

• antisubmarine
  adjective

Inflected Forms

Nouns

• submarines
  plural

Etymology

Origin of submarine

1640–50; 1895–1900 submarine for def. 1; sub- + marine

Explanation

If you're in the Navy, a submarine is a military ship that goes under the water. If you're hungry, it's a type of sandwich. This word mainly refers to a vessel that travels underwater and is armed with torpedoes — also known as a U-boat. But you can submarine someone by attacking them with a submarine or bringing them down with a blow to the legs. A disappointment can submarine — or sink — your hopes and dreams. In the kitchen, a submarine is what you call a long, crusty sandwich filled with meats and cheese — also known as a sub, grinder, hero, or hoagie.

Example Sentences

A Chinese submarine test-fired a "strategic" missile carrying a dummy warhead on Monday, with monitors saying the rocket appeared to land in a patch of ocean somewhere between Solomon Islands, Nauru and Tuvalu.

From Barron's • Jul. 8, 2026

The U.S. submarine campaign against Japan offers another comparison: It strangled Tokyo’s economy and war effort by destroying the shipping that carried fuel, food and raw materials.

From The Wall Street Journal • Jul. 7, 2026

Competition for the submarine contract has been similarly fierce.

From The Wall Street Journal • Jul. 6, 2026

Until recently, the Scottish government would refuse to hand over public money to support munitions manufacture, prompting a warning that plans for a specialist submarine welding centre on the Clyde might be scuppered.

From BBC • Jul. 1, 2026

And the bigger the hole got, the faster the boat sank, as if it were tired of being a boat and wanted to try being a submarine.

From "Nim’s Island" by Wendy Orr

Related Words

• sub
• torpedo