A covering for all or part of the face, worn as a disguise, or to amuse or terrify other people. A covering made of fiber or gauze and fitting over the nose and mouth to protect against dust or air pollutants, or made of sterile gauze and worn to prevent infection of the wearer or (in surgery) of the patient. A likeness of a person's face in clay or wax, especially one made by taking a mold from the face. A manner or expression that hides one's true character or feelings; a pretense. A piece of something, such as a card, used to cover a part of an image that is not required when exposing a print. A patterned metal film used in the manufacture of microcircuits to allow selective modification of the underlying material. The enlarged lower lip of a dragonfly larva, which can be extended to seize prey. Cover (the face) with a mask.