Plain English Meaning
The speed at which the airplane has enough lift to fly off the runway during takeoff.
Full Definition
The airspeed at which an aircraft, during the takeoff roll, develops enough lift to leave the runway and become airborne. It is specific to the aircraft type, weight, configuration, and conditions, and is published in the aircraft flight manual.
Context Anchor
Seen in takeoff, departure, and approach-to-stall discussions, especially when describing the -speed just after the aircraft becomes airborne.