submarine

US /ˌsʌb.məˈriːn/
UK /ˌsʌb.məˈriːn/
"submarine" picture
1.

a warship with a streamlined hull designed to operate completely submerged in the sea for long periods, equipped with a periscope and typically armed with torpedoes or missiles.

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The submarine surfaced after a week underwater.
They detected an enemy submarine near the coast.
1.

existing, occurring, or done under the surface of the sea.

:
They explored the submarine caves.
The earthquake caused a massive submarine landslide.
1.

to travel or operate under the surface of the sea.

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The vessel is designed to submarine for extended missions.
We watched the marine life as the mini-sub began to submarine.