1
: something that functions or operates underwater
specifically
: a naval vessel designed to operate underwater
2
: a large sandwich on a long split roll with any of a variety of fillings (such as meatballs or cold cuts, cheese, lettuce, and tomato)
called also grinder, hero, hoagie, Italian sandwich, po'boy, sub, torpedo
submarined; submarining
: to attack by or as if by a submarine : attack from beneath
: to dive or slide under something
Synonyms
Examples of submarine in a Sentence
Adjective
the submarine fossils that are to be found in coral reefs
Noun
always orders a roast beef submarine with the works
Recent Examples on the Web
Erik Klemetti, Discover Magazine, 11 Nov. 2023
The country has also done some research into developing submarine nuclear reactors, which typically (with some exceptions) use weapons-grade uranium for fuel that could serve as a stepping stone to nuclear weaponry.
—Sébastien Roblin, Popular Mechanics, 11 May 2023
See all Example Sentences for submarine 
Adjective
This eruption even gave its name to the style of shallow, submarine basaltic eruptions: Surtseyan.
—Erik Klemetti, Discover Magazine, 11 Nov. 2023
The country has also done some research into developing submarine nuclear reactors, which typically (with some exceptions) use weapons-grade uranium for fuel that could serve as a stepping stone to nuclear weaponry.
—Sébastien Roblin, Popular Mechanics, 11 May 2023
See all Example Sentences for submarine
These examples are programmatically compiled from various online sources to illustrate current usage of the word 'submarine.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.
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Cite this Entry
“Submarine.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/submarine. Accessed 4 May. 2024.
Copy CitationKids Definition
submarine
1 of 2 adjective
sub·ma·rine
ˈsəb-mə-ˌrēn 
ˌsəb-mə-ˈrēn
submarine
2 of 2 noun1
: a naval vessel designed to operate underwater
2
: a large sandwich on a long split roll
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