Plain English Meaning
It's the moment during takeoff when you pull back on the controls to lift the nose so the airplane can leave the ground.
Full Definition
The pilot action during the takeoff roll of smoothly applying back pressure to the elevator control to raise the nose to the takeoff pitch attitude, establishing the wing's angle of attack required for the airplane to lift off the runway.
Context Anchor
Encountered during takeoff, after the airplane has accelerated on the runway and just before lift-off.