mask

1. (n) A cover, or partial cover, for the face, used for disguise or protection. 2. (n) That which disguises; a pretext or subterfuge. 3. (n) (poetic) Appearance, likeness. 4. (n) A festive entertainment of dancing or other diversions, where all wear masks; a masquerade. 5. (n) A person wearing a mask. 6. (n) (architecture) A grotesque head or face, used to adorn keystones and other prominent parts, to spout water in fountains, and the like. 7. (n) (fortification) In a permanent fortification, a redoubt which protects the caponiere. 8. (n) (fortification) A screen for a battery. 9. (n) (zoology) The lower lip of the larva of a dragonfly, modified so as to form a prehensile organ. 10. (n) (publishing, film) A flat covering used to block off an unwanted portion of a scene or image. 11. (n) (computing, programming) A pattern of bits used in bitwise operations; bitmask. 12. (n) (computer graphics) A two-color (black and white) bitmap generated from an image, used to create transparency in the image. 13. (n) (heraldry) The head of a fox, shown face-on and cut off immediately behind the ears. 14. (v) (transitive) To cover (the face or something else), in order to conceal the identity or protect against injury; to cover with a mask or visor. 15. (v) (transitive) To disguise as something else. 16. (v) (transitive) To conceal from view or knowledge; to cover; to hide. 17. (v) (transitive, military) To conceal; also, to intervene in the line of. 18. (v) (transitive, military) To cover or keep in check. 19. (v) (intransitive) To take part as a masker in a masquerade. 20. (v) (intransitive) To wear a mask. 21. (v) (intransitive) To conceal or disguise one's autism; to learn, practice, and perform certain behaviors and suppress others in order to appear more neurotypical. 22. (v) (transitive) To cover or shield a part of a design or picture in order to prevent reproduction or to safeguard the surface from the colors used when working with an air brush or painting. 23. (v) (transitive, computing) To set or unset (certain bits, or binary digits, within a value) by means of a bitmask. 24. (v) (transitive, computing) To disable (an interrupt, etc.) by setting or unsetting the associated bit. 25. (n) Mesh. 26. (n) (UK dialectal, Scotland) The mesh of a net; a net; net-bag. 27. (n) (UK dialectal) Mash. 28. (v) (transitive, UK dialectal) To mash. 29. (v) (transitive, UK dialectal) (brewing) To mix malt with hot water to yield wort. 30. (v) (transitive, Scotland, Cumbria, Geordie, Northumbria, Durham dialectal) To be infused or steeped. 31. (v) (UK dialectal, Scotland, Cumbria, Geordie, Northumbria, Durham) To prepare tea in a teapot; alternative to brew. 32. (v) (transitive, UK dialectal) To bewilder; confuse. 33. (n) (obsolete) A dramatic performance in which the actors wore masks and represented mythical or allegorical characters. 34. (v) (intransitive, obsolete) To disguise oneself, to be disguised in any way. 35. (v) (Scotland, Northern England, rare, of clouds, the weather, a storm, etc) To prepare (to storm).