Definition
The single point on an airfoil where the total aerodynamic force produced by the distributed pressure differences across the wing can be considered to act. As angle of attack changes, the center of pressure moves along the chord line — generally forward as angle of attack increases and rearward as it decreases.
Plain English
It's the one spot on the wing where you can imagine all the lift being concentrated. That spot doesn't stay put — it slides forward and back along the wing depending on how the wing is meeting the air.
Context Anchor
Seen in discussions of longitudinal stability, pitch, lift, and how a wing’s airflow can make the nose tend to move up or down.
Derivation
From Latin centrum (middle point) and pressura (a pressing). The name describes exactly what it is: the middle point of all the pressing forces the air exerts on the wing.
Why Pilots Care
Forward or aft movement of the center of pressure produces nose-up or nose-down moments that the horizontal tail must counteract for the airplane to remain stable.
Analogy
If several people push on different parts of a door, you could simplify all those pushes as one combined push at one spot. The center of pressure is a similar simplifying point for the air pushing on a wing.
Grounding Statement
Picture the air pushing across the whole wing surface, but the effect being treated as if it acts at one movable spot.
Intuition Check
Do not assume “center” means the middle of the wing, and do not assume “pressure” means the point of highest pressure. The center of pressure is the single point where the combined effect of all the air pressure on the wing can be treated as acting.
Example Sentence 1
As the pilot increased angle of attack during the climb, the center of pressure shifted forward along the wing.
Example Sentence 2
The designer places the horizontal stabilizer to balance the shifting center of pressure so the airplane returns to its trimmed attitude after a disturbance.