What does submarine mean?
A submarine is a vessel designed to operate beneath the surface of the water, most often for naval defense, exploration, research, or rescue. In everyday North American English, “submarine” can also mean a substantial sandwich made by filling a split roll with meat, vegetables, cheese, or other ingredients. The word also functions as an adjective for things located or designed for use underwater, and, less commonly, as a verb meaning to travel or operate underwater in such a vessel. Its imagery is strongly associated with stealth, engineering, isolation, and human exploration. From submarines navigating under polar ice to crews living beneath the sea for extended periods, the word evokes both technological achievement and the unusual experience of making the ocean’s depths temporarily habitable.
A vessel designed to travel beneath the surface of the water, especially for military, scientific, or exploratory purposes.
"The submarine returned to port after a week beneath the sea."
The military sense is common in both British and American English.
In North American English, a long sandwich made with a split roll and filled with ingredients such as meat, cheese, or vegetables.
"He bought a submarine sandwich for lunch."
To travel or operate underwater in a submarine.
"The crew submarined beneath the ice to gather measurements."
This use is relatively uncommon and is most often found in technical or descriptive writing.
Situated, designed for use, or operating beneath the surface of the water.
"The researchers used a submarine camera to study the reef."
In North American English, the adjective can also describe a sandwich of the submarine type.
Used for more than one submarine; the form is also the third-person singular present of the verb in the phrase “the vessel submarines.”
"Two submarines left the harbor before dawn."
A submarine carries its own environment beneath the waves, turning the ocean into a route rather than a barrier.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does submarine come from?
The word was formed in English in the 16th century from the Latin prefix sub- meaning “under” and the Latin adjective marinus, meaning “of the sea.” The underlying root is Latin mare, “sea,” which also appears in related English words such as marine, maritime, and mariner. The compound originally referred broadly to things beneath the sea; its modern sense as a watercraft became established during the 19th century.
How submarine is actually used
The military sense is common in both British and American English. The sandwich sense is especially associated with North American informal usage. As a verb, the word is relatively uncommon and is more often found in technical or descriptive contexts.
Easily confused with submarine
A submarine is generally a vessel that travels and remains submerged, whereas a submersible is designed to be lowered into and raised from the water, often for research or underwater work.
In informal North American English, a submarine sandwich is a filled roll, not an underwater vessel.