Definition
To raise or draw in a movable aircraft component, most commonly the landing gear or wing flaps, so that it stows into its housing in the airframe after takeoff.
Plain English
To pull something back into the airplane after it is no longer needed sticking out, like the wheels or the flaps once you are climbing.
Context Anchor
Seen during the initial climb after takeoff, when the pilot may retract landing gear or flaps at the proper time and speed.
Derivation
From Latin retrahere, meaning to draw back. The 're-' part means back, and 'trahere' means to pull. So to retract is literally to pull something back in.
Why Pilots Care
Reduces aerodynamic drag, allowing a faster climb rate and better fuel efficiency after takeoff.
Intuition Check
Retract does not just mean “pull by hand.” In aircraft use, it means moving a part that was extended back to its stored or normal position.
Example Sentence 1
Once a positive rate of climb was confirmed, the pilot called 'gear up' and retracted the landing gear.
Example Sentence 2
Once safely airborne and clear of obstacles, retract the flaps one notch at a time.