This meaning refers to the space within a vehicle where the engine is housed. It is typically located at the front of the car, and access to this area is essential for maintenance and repairs.
The engine compartment has gotten hot, so I need to cool it down before working on it.
engine room (e.g. of ship)
This meaning is used in the context of ships, where it describes the area that contains the engines and machinery necessary for propulsion and power generation. Access to this space is crucial for the operation and maintenance of the ship.