Noun
airprox (plural airproxes)
(aviation) A near miss between aircraft.
Synonym: airmiss
The DH8 turboprop aircraft was on its final approach when the pilot spotted the device, a report by UK Airprox Board (UKAB) said. Source: Internet
While drones and other small, unmanned aircraft are exempt from most regulations pertaining to aircraft in general, it's still illegal to "recklessly or negligently cause or permit an aircraft to endanger any person or property", according to UK Airprox. Source: Internet