n aerodynamics, a stall is a sudden reduction in the lift forces generated by an airfoil. This most usually occurs when the critical angle of attack for the airfoil is exceeded.

Because stalls are most commonly discussed in connection with aviation, this article discusses stalls mainly as they relate to aircraft. In layman's terms, a stall in an aircraft is an event that causes the aircraft to drop suddenly (see the overview below).

Note that an aerodynamic stall does not mean that an aircraft's engines have stopped or that the aircraft has stopped moving.