Definition
A loss of lift that occurs when the wing's angle of attack exceeds the critical angle, causing the smooth airflow over the upper surface to separate and become turbulent. A stall can happen at any airspeed, any attitude, and any power setting -- it depends on angle of attack, not speed.
Plain English
When the wing meets the air at too steep an angle, the air can no longer flow smoothly over the top of it. The wing stops producing enough lift to hold the aircraft up.
Context Anchor
Seen in icing discussions because ice changes the wing’s shape and can make a stall happen sooner than the pilot expects.
Derivation
Aerodynamic' comes from Greek 'aero' (air) and 'dynamis' (force) -- relating to air in motion. 'Stall' is an old word meaning to come to a standstill or stop functioning. Together: the wing's air-driven lifting action stops working. The word is borrowed from engines (which 'stall' when they quit), but in aerodynamics it has nothing to do with the engine -- it describes the wing.
Why Pilots Care
Ice can cause an aerodynamic stall at a lower angle of attack than normal, producing an unexpected loss of control close to the ground or during approach.
Grounding Statement
Picture a wing with ice on its leading edge: the air has a harder time flowing smoothly over the wing, so the wing can quit lifting normally sooner.
Intuition Check
Do not read stall here as an engine stopping. An aerodynamic stall is about airflow over the wing breaking down and lift being lost.
Example Sentence 1
Ice on the leading edge can cause an aerodynamic stall at a lower angle of attack than the pilot expects.
Example Sentence 2
The pilot recovered from the aerodynamic stall by lowering the nose to regain smooth airflow over the wing.