Definition
To move the wing flaps from an extended (lowered) position back to the fully stowed position flush with the wing, reducing lift and drag produced by the flaps.
Plain English
Pulling the flaps back up into the wing so they are no longer sticking out into the airflow.
Context Anchor
You will see this during the after-landing roll, after the airplane is on the runway and the pilot is managing braking, steering, and cleanup.
Derivation
Retract comes from the Latin retrahere, meaning 'to draw back.' In aviation, it describes drawing a movable surface or component back into its stowed position.
Why Pilots Care
Retracting flaps after landing reduces lift so more aircraft weight rests on the wheels, improving braking effectiveness and helping prevent hydroplaning on wet runways.
Intuition Check
Retract the flaps does not mean remove the flaps or pull them back by hand. It means use the cockpit control to move them toward a less-extended position.
Example Sentence 1
After clearing the runway, the pilot retracted the flaps as part of the after-landing flow.
Example Sentence 2
In a crosswind landing the pilot waited until the airplane was firmly on the runway before retracting the flaps.