Plain English Meaning
A recorded radio message you tune into before contacting the tower or ground, telling you the latest weather and what's happening at the airport so the controller doesn't have to repeat it to every pilot.
Full Definition
A continuous broadcast of recorded non-control information at busier airports, providing arriving and departing pilots with current weather, active runways, approaches in use, and other essential airport conditions. Each broadcast is identified by a phonetic letter (Alpha, Bravo, Charlie, etc.) that updates whenever the information changes, typically once per hour or sooner if conditions warrant.
Context Anchor
Pilots usually hear ATIS on a , , or before entering the around a .