mask

verb

masked; masking; masks

transitive verb

1

: to provide or conceal (someone or something) with a mask: such as

a

: to conceal (something) from view

mask a gun battery

The entrance was masked by shrubs and flowers.

b

: to make (something) indistinct or imperceptible

masks undesirable flavors

mask the smell with a scented candle

[Dr. Joseph] Murray cautioned that people who go gluten-free to ease stomach problems may end up masking the symptoms of underlying conditions such as Crohn's disease, an immune disorder that affects the digestive tract.

—Kiera Butler

c

: to hide or conceal (something, such as one's motives or feelings)

The excuse masked his real purpose.

… a practiced yet futile attempt to mask embarrassment or anger with a smile …

—David Remnick

2

: to cover (the face or part of the face) with or as if with a mask

The low hood masked her eyes.

The leader masked his face with a scarf, her mother says, but she recognized the raspy voice of their neighbor …

—National Geographic

3

: to cover (something) for protection

Painters frequently use tape to mask … adjacent surfaces such as walls or trim.

—Gwen Bruno

4

: to modify the size or shape of (something, such as a photograph) by means of an opaque border

intransitive verb

1

a

: to put on a mask : to cover the face with a mask

As workplaces reopen, employees must mask and wash hands frequently.

—Robert A. Weinstein and Cory Franklin

—often used with up

On a recent weekend, we masked up and went for a bicycle ride in Tokyo.

—Motoko Rich and Noriko Hayashi

b

: to disguise one's true character or intentions

2

: to take part in a masquerade

masklike

ˈmask-ˌlīk 

adjective

Synonyms of mask

• disguise
• camouflage
• conceal
• hide

Choose the Right Synonym for mask

disguise, cloak, mask mean to alter the dress or appearance of so as to conceal the identity or true nature.

disguise implies a change in appearance or behavior that misleads by presenting a different apparent identity.

disguised herself as a peasant

cloak suggests a means of hiding a movement or an intention.

cloaked their maneuvers in secrecy

mask suggests some often obvious means of hiding or disguising something.

smiling to mask his discontent

Examples of mask in a Sentence

The house was masked by trees.

They tried to mask their real purpose.

She tried using perfume to mask the bad odor.

Recent Examples on the Web

But the news organizations found multiple examples where that system masked the company running the bus lines. —Willoughby Mariano, ProPublica, 8 June 2026

Those final outcomes, however, mask just how wild this 2026 French Open was. —Lev Akabas, Sportico.com, 7 June 2026

Benefits of Using Lemon Peels Adding lemon peels to your garden can boost soil health, deter pests, and even mask unpleasant odors like manure or compost. —Natalia Gonzalez Blanco Serrano, The Spruce, 7 June 2026

Unlike an Old Fashioned or Manhattan, where the whiskey truly takes center stage, Branch Water is a lighter thanks to the brightness of the grapefruit, the refreshingness of the cucumber, and sparkling water that mellows everything out without masking the spirit altogether. —Cameron Beall, Southern Living, 6 June 2026

Word History

First Known Use

1539, in the meaning defined at intransitive sense 2

Phrases Containing mask

• death mask
• face mask
• face mask penalty
• gas mask
• mask acne
• oxygen mask
• procedural face mask
• procedural mask
• procedure face mask
• procedure mask
• shadow mask
• ski mask
• surgical mask

Rhymes for mask

• ask
• bask
• basque
• cask
• casque
• flask
• masque
• pasch
• task
• subtask
• unmask

Kids Definition

mask

1 of 2 noun

ˈmask 

1

a

: a cover or partial cover for the face used for disguise

a Halloween mask

b

: masker

c

: a sculptured face made by a mold in plaster or wax

2

: something that disguises or conceals : cloak

3

a

: a covering used to protect the face

a baseball catcher's mask

b

: gas mask

c

: a device covering the nose and mouth to make it easier to inhale something

an oxygen mask

d

: a similar device or covering (as of synthetic fiber or cotton fabric) to prevent inhalation of dangerous substances or to prevent the inhalation or dispersal of exhaled infectious material (as viruses)

4

: the head or face of a mammal (as a fox or dog)

5

: masque sense 2

mask

2 of 2 verb

1

: to put on or wear a mask

2

a

: conceal, disguise

masked their real purpose

b

: to make impossible to perceive or distinguish

masks undesirable flavors

3

: to cover for protection

Medical Definition

mask

1 of 2 noun

ˈmask 

1

: a protective covering for the face or part of the face

2

a

: a device usually covering the mouth and nose to facilitate delivery of a gas (such as a general anesthetic) see also oxygen mask

b

: a comparable device or covering (as of polypropylene fiber or cotton fabric) worn to prevent inhalation of dangerous substances or to prevent the inhalation or dispersal of exhaled infectious material (such as bacteria or viruses) see also face mask, gas mask, procedure mask, surgical mask

3

: a cosmetic preparation for the skin of the face that produces a tightening effect as it dries

mask

2 of 2 transitive verb

1

: to prevent (an atom or group of atoms) from showing its ordinary reactions

to mask hydroxyl in a sugar by converting it into methoxyl

2

: to modify or reduce the effect or activity of (as a process or a reaction)

3

: to make indistinct or imperceptible

flavorings used in pharmacy to mask the taste of medications

4

: to raise the audibility threshold of (a sound) by the simultaneous presentation of another sound