This might be a more helpful definition.
What is "feathering the clutch?"
Feathering the clutch is the proper way to activate the clutch pedal when changing gears. That is, rather than a sudden, jerky release of the clutch pedal, you ease-out when releasing it. This reduces stress not only on clutch components, but the entire drivetrain. The engine RPMs should match closely to that of the selected gear you're shifting into as well (see "double clutching").
There is a fine line between sudden release, feathering and letting the clutch slip. Practice this and prolong the life of your clutch! If you smell something burning, or the engine wails as you release, the clutch is slipping.
cited here