| fin [fin] AEROSPACE ENGINEERING A fixed or adjustable vane or airfoil affixed longitudinally to an aerodynamically or ballistically designed body for stabilizing purposes. DESIGN ENGINEERING A projecting flat plate or structure, as a cooling fin. ENGINEERING Material which remains in the holes of a molded part and which must be removed. VERTEBRATE ZOOLOGY A paddle-shaped appendage on fish and other aquatic animals that is used for propulsion, balance, and guidance. |