Plain English Meaning
The airplane has too much speed as you level off just above the runway, so instead of settling gently onto the wheels it keeps flying along a few feet up. You drift down the runway in this hovering state until the speed bleeds off enough for the airplane to land.
Full Definition
A landing error in which the airplane, after the round out, remains airborne longer than expected and travels down the runway at low altitude before touching down. It is typically caused by carrying excess airspeed into the round out, which leaves the wing with more lift than needed to settle the airplane onto the runway.
Context Anchor
Encountered during the last part of a landing, just before touchdown, when the pilot is reducing the and preparing the airplane to land.