Plain English Meaning
An automatic weather station at an airport that measures the local weather and reads it out loud over a radio frequency so pilots can hear current conditions before taking off or landing.
Full Definition
A ground-based, automated system that continuously measures local weather conditions at or near an airport and broadcasts the results by radio and, at many sites, by telephone. AWOS sensors typically report wind speed and direction, temperature, dew point, , , and , with the elements depending on the AWOS (AWOS-A, A/V, 1, 2, 3, 3P/T/PT, and 4) installed at that location.