submarine
The French word for 'submarine' is 'sous-marin'. It is used similar to English, referring to a type of ship that can operate underwater. It can be used in various contexts, but is most often associated with naval and marine activities.
I like to eat a submarine sandwich for lunch.
In this sentence, 'sous-marin' refers to a type of sandwich often known as a submarine sandwich, so called because its shape resembles a submarine. This kind of sandwich is quite popular, and contains various kinds of fillings inside a long roll of bread.
The submarine disappeared into the ocean.
Here, 'sous-marin' is used in its most common sense, referring to a naval vehicle designed to operate underwater. Submarines are used in various contexts, such as scientific research, warfare, or exploration.
He is reading a book about the history of submarines.
In this sentence, 'sous-marins' is used to refer to submarines in a historical context. This suggests that the person is reading a book about the development and usage of submarines throughout history.