mask

noun

1. A cover, or partial cover, for the face, used for disguise or protection.

   “a dancer's mask; a fencer's mask; a ball player's mask”

   “Just a few days ago, the Centers for Disease Control and Prevention—the CDC—issued new mask guidelines. Under these new guidelines, most Americans in most of the country can now be mask free. And based on the projections, more of the country will reach that point across the next couple of weeks.”

2. That which disguises; a pretext or subterfuge.

   “Grouchy and wary and tender, he’s a sozzled hedonist seemingly out for himself—though his party-animal facade is just a mask for his bottomless generosity.”

3. (poetic)Appearance, likeness.

   “Come then, pure hands, and bear the head ⁠That sleeps or wears the mask of sleep, ⁠And come, whatever loves to weep, And hear the ritual of the dead.”

4. A festive entertainment of dancing or other diversions, where all wear masks; a masquerade.

   “This thought might lead me through the world's vain mask.”

5. A person wearing a mask.

   “the mask that has the arm of the Indian queen”

   “Jones, now taking the mask by the hand, fell to entreating her in the most earnest manner, to acquaint him where he might find Sophia; and when he could obtain no direct answer, he began to upbraid her gently […]”

6. (obsolete)A dramatic performance in which the actors wore masks and represented mythical or allegorical characters.
7. A grotesque head or face, used to adorn keystones and other prominent parts, to spout water in fountains, and the like.
8. In a permanent fortification, a redoubt which protects the caponiere.
9. A screen for a battery.
10. The lower lip of the larva of a dragonfly, modified so as to form a prehensile organ.
11. A flat covering used to block off an unwanted portion of a scene or image.
12. A pattern of bits used in bitwise operations; bitmask.
13. A two-color (black and white) bitmap generated from an image, used to create transparency in the image.
14. The head of a fox, shown face-on and cut off immediately behind the ears.
15. Mesh.
16. (Scotland, UK, dialectal)The mesh of a net; a net; net-bag.
17. (UK, dialectal)Mash.

verb

1. (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.

   “They must all be masked and vizarded”

2. (transitive)To disguise as something else.
3. (transitive)To conceal from view or knowledge; to cover; to hide.

   “Masking the business from the common eye”

   “The opponent must not be able to recognize when we inhale and when we exhale. We achieve this by breathing with the diaphragm and we do not raise the shoulders while breathing. In particular we must mask when we are out of breath.”

   “Many autistic people have language and cognitive skills; [and] they mask their autism, cover up social discomfort, and work hard to be someone they are not, so people often see them as “fitting in” just fine.”

4. (transitive)To conceal; also, to intervene in the line of.
5. (transitive)To cover or keep in check.

   “to mask a body of troops or a fortess by a superior force, while some hostile evolution is being carried out”

6. (intransitive)To take part as a masker in a masquerade.

   “Come Pentecost as quickly as it will, Some five and twenty years, and then we mask’d.”

   “noble Gentilmen / who daunced & masked wt thes fayer ladyes & gentillwomen”

7. (intransitive)To put on a mask; to wear a mask.

   “Dr. Shelita Dattani, director of professional affairs at the Canadian Pharmacists Association, says […]. “The efforts that we’re taking to reduce the spread of COVID are working … people are masking and distancing and staying away from each other and using hand hygiene, so I think all of these efforts combined are contributing to lower rates.””

8. (intransitive, obsolete)To disguise oneself, to be disguised in any way.

   “Ioue sometime maſked in a ſhepheards weede, And by thoſe ſteps that he hath ſcal’d the heauens, May we become immortall like the Gods.”

9. (intransitive)To conceal or disguise one's autism; to learn, practice, and perform certain behaviors and suppress others in order to appear more neurotypical.

   “Masking is exhausting and some autistics require copious amounts of time afterwards to recover from hiding who they are and pretending to be someone they aren't. Even when autistics mask they don't always pass fully as an NT person.”

   “Masking can leave a person with less energy to handle other aspects of their day, from performing basic housework to processing thoughts and feelings.”

   “So, masking seems to be a very poor explanation for the difference in gender diagnosis of autism. In particular, masking requires theory of mind. How can autistic people successfully mask if they struggle with this ability?”

   “Some group members describe masking during therapy in order to seem more likeable to the therapist, or because they felt it necessary in order to be seen as engaging with the support.”

   “Kayleigh, who was finally diagnosed at 18, felt that she masked a lot growing up because she "always felt different and was bullied if [she] showed it both at home and in school".”

10. (transitive)To cover or shield something, or a portion of something, so as to prevent reproduction or to safeguard the surface from the colors used when working with an air brush or painting.
11. (transitive)To set or unset (certain bits, or binary digits, within a value) by means of a bitmask.

    “That is, the lower nibble (the 4 bits 1010 = A) has been masked to zero. This is because ANDing anything with a zero produces a zero, while ANDing any bit with a 1 leaves the bit unchanged[…]”

12. (transitive)To disable (an interrupt, etc.) by setting or unsetting the associated bit.

    “Some hardware interrupts can be masked, or disabled; that is, the CPU is told to ignore them.”

13. (UK, dialectal, transitive)To mash.
14. (UK, dialectal, transitive)(brewing) To mix malt with hot water to yield wort.
15. (Cumbria, Durham, Geordie, Northumbria, Scotland, dialectal, transitive)To be infused or steeped.
16. (Cumbria, Durham, Geordie, Northumbria, Scotland, UK, dialectal)To prepare tea in a teapot; alternative to brew.
17. (Northern-England, Scotland, rare)To prepare (to storm).

    “I saw the storm was masking fast, That soon wad fa' on me;[…]”

    “... mirky cluds in the south-wast / Are masking up a blashy blast, ...”

    “The whislin' key hole o the door / Fou plainly tells a storm is maskin'.”

18. (UK, dialectal, transitive)To bewilder; confuse.