Plain English Meaning

Flying noticeably slower than usual on purpose, so the pilot can practice handling the airplane when it feels heavy, sluggish, and close to stalling.

Full Definition

Airspeeds slower than normal cruise or maneuvering speeds, typically flown intentionally during training or specific phases of flight to develop the pilot's feel for the airplane's handling and control response as it approaches the lower end of its flight envelope. In the slow flight context, reduced airspeeds are speeds below the airplane's design maneuvering speed and approaching the stall warning regime, where control effectiveness decreases and the airplane requires higher and more to .