Plain English Meaning
These are engine failures that happen so close to the ground that the pilot has very little time and very few options. The right action depends on exactly when the failure occurs — still on the runway, just airborne, climbing out, or in the pattern.
Full Definition
A category of engine failure situations occurring at altitudes too low to permit a normal glide and landing, generally including failures during the takeoff roll, immediately after liftoff, during the initial climb, and in the traffic pattern. Each has a recommended based on , , remaining runway, and surrounding .