Definition
In a takeoff, the action of the airplane pitching nose-up about its lateral axis as the pilot applies back pressure on the controls at the appropriate airspeed, raising the nose to the takeoff attitude so the wings can produce enough lift to leave the runway.
Plain English
The airplane lifts its nose off the runway when the pilot pulls back on the controls at the right speed during takeoff. After the nose comes up, the airplane lifts off shortly after.
Context Anchor
Seen in discussions of airplane control, pitch attitude, takeoff, landing, stall recovery, and sink-rate control.
Derivation
From Latin 'rotare', meaning 'to turn'. In flying, the airplane is turning about its lateral axis (the wingtip-to-wingtip line) as the nose comes up. Knowing this helps make clear that 'rotate' here is not about spinning around a vertical axis -- it is the nose pivoting upward.
Why Pilots Care
Rotating at the correct speed and rate ensures the aircraft becomes airborne with adequate airspeed and climb performance; rotating too early or too late can produce excessive drag, tail strikes, or runway overruns.
Intuition Check
Do not read “rotates” here as only meaning a full spin or a turn around the horizon. In this context, the airplane may rotate only a few degrees, such as the nose pitching up or down.
Example Sentence 1
At the calculated airspeed, the pilot smoothly rotates the airplane to the takeoff pitch attitude and the airplane lifts off shortly after.
Example Sentence 2
Rotating too late forces the aircraft to remain on the runway longer than necessary.