<p><strong>Noun</strong></p><ul><li>A covering for all or part of the face, worn to conceal one's identity.</li><li>A grotesque or humorous false face worn at a carnival, masquerade, etc.: Halloween masks.</li><li>Also called swim mask: a device consisting typically of a transparent glass or plastic panel fitted into a flexible rubber gasket that fits snugly around the eyes, over the cheeks, and usually over the nose; used by skin divers.</li><li>Anything that disguises or conceals; disguise; pretense: His politeness is a mask for his fundamentally malicious personality.</li><li>A likeness of a face, as one molded on the face in plaster.</li><li>A covering of wire, gauze, etc., to protect the face, as from splinters, dust, or a pitched ball.</li><li>Gas mask: any protective covering for the face or head.</li><li>Any protective covering, as paper, cardboard, plastic, or the like, used for masking an area of something, as of a photograph or window.</li><li>The dark shading on the muzzle of certain dogs.</li><li>A representation of a face or head, generally grotesque, used as an architectural ornament or as a decorative device in weaponry, furniture, etc.</li><li>A person wearing a mask; masker.</li><li>Masque: also a cosmetic cream, gel, paste, or the like, that is applied to the face and allowed to remain for a short time before being removed and is used for tightening, cleansing, refreshing, or lubricating the skin.</li><li>A piece of cloth, silk, or plastic material covering the face of an actor to symbolize the character being represented: used in Greek and Roman drama and in some modern plays.</li><li>The face or head, as of a fox.</li><li>Electronics: a type of stencil applied to the surface of a semiconductor to permit selective etching or deposition; used in the manufacture of integrated circuits by photolithography.</li><li>Fortification: a screen, as of earth or brush, for concealing or protecting a battery or any military operation.</li><li>Also called braker: Shipbuilding: a sliding timber construction braced against the stern of a hull being launched to keep it from entering the water too rapidly.</li></ul><p><strong>Verb</strong></p><ul><li>(Used with object) to disguise or conceal; hide; dissemble: to mask one's intentions.</li><li>Synonyms: cover, cloak, screen, veil.</li><li>To cover or conceal with a mask.</li><li>To cover or shield a part of (a design, picture, etc.) in order to prevent reproduction or to protect the surface from the colors used, as in working with an air brush or in painting.</li><li>Fortification: to conceal (a battery or any military operation) from the enemy.</li><li>To hinder, as an army, from conducting an operation.</li><li>(Used without object) to put on a mask; disguise oneself.</li></ul>