Plain English Meaning
A button label on the cockpit display that means 'Airport.' Pressing it brings up details about a nearby airport.
Full Definition
On the Garmin G1000 (and similar) Nearest Airports page, APR is a soft key label that filters or selects the Airport entry, allowing the pilot to view information about the nearest airports such as identifier, distance, bearing, runway length, and frequencies.
Context Anchor
Seen on an avionics Nearest Airports page when reviewing details for a nearby airport.
Derivation
APR stands for approach, from the Latin 'appropinquare' meaning to come near, referring to the procedures that guide the aircraft safely to the runway.