Plain English Meaning
The people up front who actually fly the airplane and are responsible for getting it from A to B safely.
Full Definition
The qualified personnel responsible for operating an aircraft in flight, typically including the pilot in command and, depending on the aircraft and operation, a second in command, flight engineer, or other required crewmembers whose duties are essential to the safe operation of the aircraft.
Context Anchor
Seen in abnormal and emergency procedures, where the text describes what the people operating the aircraft should notice, check, or do.
Derivation
A simple compound of 'flight' and 'crew.' 'Crew' comes from Old French 'creue,' meaning a band or group assembled for a task. The word emphasizes that flying is a job, not a activity, even when only one is on board.