Source : Webster's Revised Unabridged Dictionary (1913)
Mask \Mask\, n. [F. masque, LL. masca, mascha, mascus; cf. Sp. &
Pg. m['a]scara, 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. (Zo["o]l.) The lower lip of the larva of a dragon fly,
modified so as to form a prehensile organ.
{Mask house}, a house for masquerades. [Obs.]