Mask (?), n. [F. masque, LL. masca, mascha, mascus; cf. Sp. & Pg. máscara, It. maschera; all fr. Ar. maskharat buffoon, fool, pleasantry, anything ridiculous or mirthful, fr. sakhira to ridicule, to laugh at. Cf. Masque, Masquerade.] 1. A cover, or partial cover, for the face, used for disguise or protection; as, a dancer's mask; a fencer's mask; a ball player's mask.
2. That which disguises; a pretext or subterfuge.
3. A festive entertainment of dancing or other diversions, where all wear masks; a masquerade; hence, a revel; a frolic; a delusive show. Bacon.
This thought might lead me through the world's vain mask. Milton.
4. A dramatic performance, formerly in vogue, in which the actors wore masks and represented mythical or allegorical characters.
5. (Arch.) A grotesque head or face, used to adorn keystones and other prominent parts, to spout water in fountains, and the like; — called also mascaron.
6. (Fort.) (a) In a permanent fortification, a redoubt which protects the caponiere. (b) A screen for a battery.
7. (Zoöl.) The lower lip of the larva of a dragon fly, modified so as to form a prehensile organ.
Mask house, a house for masquerades.