Plain English Meaning
Things that go wrong while you are flying that you have to deal with right away to keep the flight safe.
Full Definition
Unplanned situations that arise during flight and require immediate action by the pilot to protect the safety of the aircraft and its occupants. These include mechanical failures, medical issues, weather encounters, fire, fuel problems, control difficulties, and any other condition that compromises the safe continuation of flight.
Context Anchor
Seen in pilot health, safety, and emergency-procedure discussions, especially when a problem happens after takeoff and before landing.
Derivation
‘Inflight’ simply means ‘during flight,’ and ‘emergency’ comes from the Latin ‘emergere,’ meaning ‘to rise up’ or ‘come forth.’ The sense is of something that suddenly arises and demands — which captures the : an emergency is not just a problem, it is a problem that has surfaced and must be handled now.