compartment one of the separate areas into which a plane,ship,or train is divided There are ten compartments in each car of the train. The non-smoking compartment is in the middle of the train. one of the separate parts of sth.such as a desk or box,where you can keep things Put the ice cream back in the freezer compartment. The dresser drawer was partitioned into four compartments.compartment • one of the separate areas into which a plane, ship, or train is divided There are ten compartments in each car of the train. The non-smoking compartment is in the middle of the train. • one of the separate parts of sth. such as a desk or box, where you can keep things Put the ice cream back in the freezer compartment. The dresser drawer was partitioned into four compartments