Plain English Meaning
Leveling off for landing too far above the runway, so the airplane runs out of speed before the wheels can reach the ground.
Full Definition
A landing error in which the pilot begins the round out (the transition from descent to level flight just before touchdown) too high above the runway, leaving the airplane suspended above the surface with decaying airspeed and insufficient height for a normal touchdown.
Context Anchor
Encountered during landing practice, especially while the round out and just before touchdown.