What action is indicated by the term "Enplane"?

The term "Enplane" specifically refers to the action of passengers boarding an aircraft. It derives from the words "in" and "plane," indicating that individuals are entering the plane to take their seats. This term is commonly used in the aviation and airline industry to distinguish the process of passengers getting onto the aircraft from other related processes, such as checking in or deplaning, which is associated with passengers exiting the aircraft after a flight.

In contrast, the other options refer to different stages of the travel process. For instance, deplaning is the opposite of enplaning and involves passengers leaving the aircraft. Checking in requires passengers to confirm their presence on a flight and receive boarding passes, while waiting in the terminal pertains to the time spent at the airport before boarding their flight. Each of these activities is an important part of air travel, but they do not specifically define the act of boarding the aircraft, which is encapsulated by the term "enplane."