# submarine

/ˈsəbmɝˌin/ (US) · /sˈʌbməɹˌiːn/ (UK)

Source: https://englishreference.com/word/submarine
Updated: 2026-06-20

## Senses

### 1. underwater vessel

noun · CEFR A2

a ship that can travel deep under the ocean for a long time.

For teachers: a naval vessel capable of independent operation underwater, typically used for military or research purposes.

- The submarine stayed under the water for three months without coming up.
- Modern nuclear submarines are capable of remaining submerged for months at a time, limited only by the food supplies required for the crew.

### 2. a long sandwich

noun · CEFR B1 · American English · Informal

a long bread roll filled with meat, cheese, and vegetables.

For teachers: a large sandwich consisting of a long crusty roll split lengthwise and filled with various meats and cheeses.

- I ordered a turkey submarine with extra pickles for lunch.
- The local deli is famous for its massive submarines, which are packed with imported Italian meats and a signature vinaigrette.

### 3. underwater

adjective · CEFR B2

happening or existing beneath the surface of the sea.

For teachers: existing, occurring, or used under the surface of the sea.

- Scientists are studying submarine volcanoes to see how they change the ocean floor.
- The company specialises in the maintenance of submarine cables that provide high-speed internet across the Atlantic.

### 4. to slide under

verb · CEFR C1 · Technical

to slide forward and under something, like a seatbelt during a car crash.

For teachers: to slide forward underneath a restraint, such as a lap belt, during a sudden deceleration or collision.

- The crash test dummy started to submarine because the seatbelt was too loose.
- Engineers redesigned the seat base to prevent passengers from submarining during a high-impact frontal collision.

Usage: The verb is intransitive in this safety-testing context.

## Examples

- The submarine dives deep under the ocean waves.
- Scientists used a small research submarine to explore the wreckage on the sea floor.
- Modern nuclear submarines can remain submerged for months at a time, providing a stealthy platform for both scientific observation and strategic military deterrence.

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From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.