['mæskәˏrɔn]
怪头(在拱顶石上), 怪状面具

Mask \Mask\ (m[.a]sk), 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.

8. A person wearing a mask; a masker.

The mask that has the arm of the Indian queen. --G.
W. Cable.
[Webster 1913 Suppl.]

9. (Sporting) The head or face of a fox.

{Mask house}, a house for masquerades. [Obs.]

{Death mask}, a cast of the face of a dead person.