Plain English Meaning
It is the official radio service that lets aircraft talk to ground stations and to each other. The frequencies pilots use to talk on the radio belong to this service.
Full Definition
A radio communication service, defined by international agreement, between aircraft stations and aeronautical ground stations, or between aircraft stations themselves, in which survival craft stations may also participate. It uses designated frequencies allocated specifically for aviation use.
Context Anchor
Seen in radio equipment discussions, aircraft radio licensing, and descriptions of the aviation communication frequencies used during flight.
Derivation
‘Aeronautical’ comes from Latin and Greek roots meaning ‘relating to flight through the air.’ ‘Mobile’ here means the stations are not fixed in one place — at least one end of the conversation is moving (the aircraft). So the name simply describes what it is: a radio service for moving aircraft.