Definition
A fairing or shaped extension fitted to the leading edge or root of a wing, propeller blade, or other airfoil to alter its aerodynamic shape. On wings, a leading-edge cuff modifies the airfoil profile to improve stall characteristics and low-speed handling. On propellers, a blade cuff is a wide, airfoil-shaped sleeve fitted around the blade shank near the hub to convert that otherwise non-lifting area into a useful airflow surface and to direct cooling air through the engine cowling.
Plain English
A shaped add-on fitted to part of a wing or propeller blade to change how air flows over it. On wings it usually improves stall behavior. On propellers it turns the round, non-lifting part near the hub into a working airfoil and helps push cooling air into the engine.
Context Anchor
Seen in aircraft maintenance, propeller descriptions, and wing-design discussions.
Derivation
From the everyday meaning of cuff -- a band wrapped around the end of a sleeve or trouser leg. The aviation term borrows the same image: a shaped band fitted around the root of a propeller blade, or along the leading edge of a wing, to modify what's already there.
Why Pilots Care
Proper cuffs maintain designed thrust and efficiency; damage or missing cuffs reduce performance and can affect engine loading.
Analogy
A clothing cuff wraps around the end of a sleeve. An aircraft cuff similarly wraps around or extends over a part, but its job is to shape the airflow.
Intuition Check
Cuff does not mean clothing here. It means a shaped aircraft part that wraps around or extends from another part to guide airflow.
Example Sentence 1
The leading-edge cuff installed on the wing gave the aircraft a gentler stall and better low-speed control.
Example Sentence 2
During the preflight walk-around the pilot checked each propeller cuff for cracks or loose fasteners.