Definition
The speed of an object in a specified direction. In aviation, velocity is used when both how fast something is moving and which way it is moving matter — for example, the airplane's motion through the air, the relative wind, or the flow of air over a wing.
Plain English
How fast something is moving and the direction it's moving in.
Context Anchor
Seen in discussions of airplane feel, airflow over the wings and control surfaces, and how control response changes as the airplane speeds up or slows down.
Derivation
From Latin velocitas, meaning 'swiftness' or 'speed.' In physics and aviation it picked up the added requirement of direction, which is what separates velocity from plain speed.
Why Pilots Care
Velocity affects wind correction, ground track, and energy management; confusing it with speed alone can lead to incorrect drift or descent calculations.
Analogy
A car going 60 miles per hour tells you its speed. A car going 60 miles per hour north gives you its velocity, because now you know both how fast it is moving and which way it is going.
Intuition Check
Do not treat velocity as just another word for speed. Speed tells how fast; velocity tells how fast and in what direction.
Example Sentence 1
As the airplane accelerates down the runway, the velocity of the air over the wings increases until it generates enough lift for takeoff.
Example Sentence 2
Changing wind velocity required the pilot to adjust heading to stay on the intended ground track.