bentgear gave good explanations, but I'm going to take a shot at it in English.

Stall - Your aircraft stopped flying and is now falling from the sky.

Washout - Wing tips are twisted so the leading edge is lower at the tip than at the center and trailing edge is higher than at the center. This makes the wingtips keep flying after the center of the wing has stalled and prevents your plane from flipping over on its back.

Incidence. Incidence is the angle at which your wing or stabilizer is mounted when viewed from the side. Zero = level. Positive numbers indicated the leading edge is higher than the trailing edge. Negative indicates the trailing edge is higher than the leading edge. Same goes for stabilizer.