A Quick and Simple Dictionary

mask

1. Noun.  A cover, or partial cover, for the face, used for disguise or protection.
2. Noun.  That which disguises; a pretext or subterfuge.
3. Noun.  A festive entertainment of dancing or other diversions, where all wear masks; a masquerade; hence, a revel; a frolic; a delusive show - Francis Bacon.
4. Noun.  (obsolete) A dramatic performance, formerly in vogue, in which the actors wore masks and represented mythical or allegorical characters.
5. Noun.  (architecture) 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. Noun.  (context, fortification) In a permanent fortification, a redoubt which protects the caponiere.
7. Noun.  (context, fortification) A screen for a battery.
8. Noun.  (zoology) The lower lip of the larva of a dragonfly, modified so as to form a prehensile organ.
9. Noun.  (context, Puebloan) A ceremonial object used in Puebloan kachina cults that resembles a Euro-American masks. (The term is objected as an appropriate translation by Puebloan peoples as it emphasizes imitation but ignores power and representational intent.).
10. Noun.  (computing, programming) A pattern of bits used in bitwise operations; bitmask.
11. Noun.  (computer graphics) A two-color (black and white) bitmap generated from an image, used to create transparency in the image.
12. Verb.  (transitive) To cover, as the face, by way of concealment or defense against injury; to conceal with a mask or visor.
13. Verb.  (transitive) To disguise; to cover; to hide.
14. Verb.  (transitive, military) To conceal; also, to intervene in the line of.
15. Verb.  (transitive, military) To cover or keep in check.
16. Verb.  (intransitive) To take part as a masker in a masquerade.
17. Verb.  (intransitive) To wear a mask; to be disguised in any way.