Plain English Meaning

The wing has been pulled up to such a steep angle that it can no longer hold the airplane up. The nose drops, the airplane starts sinking, and the pilot is holding the controls all the way back. The pilot then recovers from this fully developed condition rather than catching it early.

Full Definition

A stall in which the airplane's angle of attack has been increased to the point where the wing has reached its maximum lift capability and lift has broken down across most of the wing, typically accompanied by a clear nose drop, a high sink rate, and full aft control yoke or stick. It is the deepest of a practiced stall, distinguished from an -to-stall or imminent stall, where is initiated at the first indication.