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• mass
  mass

  noun

  a body of coherent matter, usually of indefinite shape and often of considerable size.
• Mass
  Mass

  noun

  the celebration of the Eucharist.
• Mass.
  Mass.

  abbreviation

  Massachusetts.

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mass

¹ American  

[mas] / mæs /

noun

• masses
  plural

1. a body of coherent matter, usually of indefinite shape and often of considerable size.

   a mass of dough.

2. Medicine/Medical, Pathology. an abnormal lump in the body, often in the form of a cyst or tumor.

   The mass they removed was alarmingly large, but the great news is that it was benign.

3. a collection of incoherent particles, parts, or objects regarded as forming one body.

   a mass of sand.

   Synonyms:

   congeries, heap, assemblage

4. aggregate; whole (usually preceded byin the ).

   People, in the mass, mean well.

5. a considerable assemblage, number, or quantity: a mass of troops.

   a mass of errors;

   a mass of troops.

   Synonyms:

   conglomeration, pile, accumulation, collection

6. bulk, size, expanse, or massiveness.

   towers of great mass and strength.

   Synonyms:

   dimension, magnitude

7. Fine Arts.

   1. Painting. an expanse of color or tone that defines form or shape in general outline rather than in detail.

   2. a shape or three-dimensional volume that has or gives the illusion of having weight, density, and bulk.

8. the main body, bulk, or greater part of anything.

   the great mass of American films.

   Synonyms:

   majority

9. Physics. the quantity of matter as determined from its weight or from Newton's second law of motion. m

10. Pharmacology. a preparation of thick, pasty consistency, from which pills are made.

11. the masses, the ordinary or common people as a whole; the working classes or the lower social classes.

    Synonyms:

    plebeians, proletariat

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adjective

1. 1. pertaining to, involving, or affecting a large number of people.

      mass unemployment;

      mass migrations.

   2. affecting a number of people, but more than two and typically a large number: a mass shooting.

      mass murder;

      a mass shooting.

2. participated in or performed by a large number of people, especially together in a group: mass suicide.

   mass demonstrations;

   mass suicide.

3. pertaining to, involving, or characteristic of the mass of the people: a movie designed to appeal to a mass audience.

   the mass mind;

   a movie designed to appeal to a mass audience.

4. reaching or designed to reach a large number of people.

   television, newspapers, and other means of mass communication.

5. done on a large scale or in large quantities.

   mass destruction.

verb (used without object)

• masses,
  present (3rd person singular)
• massed,
  past participle,  past
• massing
  present participle

1. to come together in or form a mass or masses.

   The clouds are massing in the west.

verb (used with object)

• masses,
  present (3rd person singular)
• massed,
  past participle,  past
• massing
  present participle

1. to gather into or dispose in a mass or masses; assemble.

   The houses are massed in blocks.

   Synonyms:

   aggregate, amass, marshal, collect

   Antonyms:

   disperse

Mass ² American  

[mas] / mæs /

noun

1. the celebration of the Eucharist.

2. (sometimes lowercase) a musical setting of certain parts of this service, as the Kyrie eleison, Gloria, Credo, Sanctus, Benedictus, and Agnus Dei.

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Mass. ³ American  

abbreviation

1. Massachusetts.

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mass ¹ British  

/ mæs /

noun

1. a large coherent body of matter without a definite shape

2. a collection of the component parts of something

3. a large amount or number, such as a great body of people

4. the main part or majority

   the mass of the people voted against the government's policy

5. in the main; collectively

6. the size of a body; bulk

7. physics a physical quantity expressing the amount of matter in a body. It is a measure of a body's resistance to changes in velocity (inertial mass) and also of the force experienced in a gravitational field (gravitational mass): according to the theory of relativity, inertial and gravitational masses are equal See also inertial mass gravitational mass

8. (in painting, drawing, etc) an area of unified colour, shade, or intensity, usually denoting a solid form or plane

9. pharmacol a pastelike composition of drugs from which pills are made

10. mining an irregular deposit of ore not occurring in veins

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1. done or occurring on a large scale

   mass hysteria

   mass radiography

2. consisting of a mass or large number, esp of people

   a mass meeting

verb

1. to form (people or things) or (of people or things) to join together into a mass

   the crowd massed outside the embassy

Mass. ² British  

abbreviation

1. Massachusetts

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Mass ³ British  

/ mæs, mɑːs /

noun

1. (in the Roman Catholic Church and certain Protestant Churches) the celebration of the Eucharist See also High Mass Low Mass

2. a musical setting of those parts of the Eucharistic service sung by choir or congregation

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mass Scientific  

/ măs /

1. A measure of the amount of matter contained in or constituting a physical body. In classical mechanics, the mass of an object is related to the force required to accelerate it and hence is related to its inertia, and is essential to Newton's laws of motion. Objects that have mass interact with each other through the force of gravity. In Special Relativity, the observed mass of an object is dependent on its velocity with respect to the observer, with higher velocity entailing higher observed mass. Mass is measured in many different units; in most scientific applications, the SI unit of kilogram is used.

2. See Note at weight See also rest energy General Relativity

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Mass ¹ Cultural  

1. In music, a musical setting for the texts used in the Christian Church at the celebration of the Mass, or sacrament of Communion. Most Masses have been written for use in the Roman Catholic Church.

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Mass ² Cultural  

1. The common name in the Roman Catholic Church, and among some members of the Anglican Communion, for the sacrament of Communion.

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mass ³ Cultural  

1. In physics, the property of matter that measures its resistance to acceleration. Roughly, the mass of an object is a measure of the number of atoms in it. The basic unit of measurement for mass is the kilogram. (See Newton's laws of motion; compare weight.)

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Synonym Usage

See size ¹.

Discover More

Many composers have written Masses; among them are Johann Sebastian Bach, Franz Josef Haydn, Wolfgang Amadeus Mozart, Franz Schubert, Leonard Bernstein, and Duke Ellington.

In the Middle Ages in England, mass meant a religious feast day in honor of a specific person; thus, “Christ's Mass,” or Christmas, is the feast day of Christ; and Michaelmas is the feast day of the angel Michael.

Other Word Forms

Derived Forms

• massed
  adjective
• unmassed
  adjective
• massedly
  adverb

Inflected Forms

Nouns

• masses
  plural

Participles

• massing
  present
• massed
  past

Conjugated Forms

Present

• mass
  simple
• masses
  simple
• have massed
  perfect
• has massed
  perfect
• am massing
  progressive
• are massing
  progressive
• is massing
  progressive
• have been massing
  perfect progressive
• has been massing
  perfect progressive

Past

• massed
  simple
• had massed
  perfect
• was massing
  progressive
• were massing
  progressive
• had been massing
  perfect progressive

Future

• will mass
  simple
• will have massed
  perfect
• will be massing
  progressive
• will have been massing
  perfect progressive

Etymology

Origin of mass¹

First recorded in 1350–1400; Middle English masse, from Latin massa “mass,” from Greek mâza “barley cake,” akin to mássein “to knead”

Origin of Mass²

First recorded before 900; Middle English masse, Old English mæsse, from Vulgar Latin messa (unrecorded), from Late Latin missa, feminine of Latin missus “sent,” past participle of mittere “to send, dismiss”; perhaps extracted from a phrase in the service containing a feminine subject and missa est “(it) is sent”

Explanation

Anything that has weight and shape has mass. In fact, mass is the quality that gives things weight anywhere there's gravity. If you think about mass being about weight and shape, you can see how many of its meanings are related. If something is very big we say it has great mass — or is massive. If we talk about a large group of people, we talk about a mass demonstration or a mass of demonstrators. We refer to poor or common people as the masses — there are a lot of them. Doctors refer to tumors inside our bodies as masses.

Example Sentences

See Examples For:

mass Mass Mass. masses massed massing

During World War II, the U.S. government marshaled American companies and universities to solve medical challenges, including the mass production of penicillin.

From The Wall Street Journal ● Sep. 18, 2026

Thirty days later, the treated mice had improvements in skin thickness and bone mass, along with better performance on tests of learning, cognition, and balance.

From Science Daily ● Sep. 18, 2026

“As listening fragments, depth of fan connection arguably becomes more important to long-term artist careers than mass reach,” said Tatiana Cirisano, VP of music strategy at Midia Research.

From The Wall Street Journal ● Sep. 18, 2026

Memory problems, thinning skin, and declining bone mass may seem like separate consequences of growing older.

From Science Daily ● Sep. 18, 2026

Then he realized the sea wasn’t a sea at all, but a mass of shadows waiting to break free.

From "The Way to Rio Luna" by Zoraida Cordova

When Mr. Freeman was promoted to head football coach at Notre Dame in 2021, one of his first priorities was to reinstate pregame Mass for the team.

From The Wall Street Journal ● Sep. 17, 2026

The team at Mass General Brigham hospital say their work shows pig organs can be used as a "bridge" until a human transplant becomes available.

From BBC ● Sep. 3, 2026

Mass layoffs are coming to another San Diego-based food company.

From Los Angeles Times ● Aug. 21, 2026

Researchers from the University of Liverpool's Mass Spectrometry Research Group conducted protein sequencing and mass spectrometry tests.

From Science Daily ● Aug. 14, 2026

The church bell now began to toll again, as if a Mass were being announced.

From "Crispin: The Cross of Lead" by Avi

Jonathan Pearl has kept his home in Marlborough, Mass., even though he has moved out of state for a job opportunity.

From The Wall Street Journal ● Sep. 15, 2026

At a team dinner in Cambridge, Mass., on Thursday, staff decided to review all risk-management systems.

From The Wall Street Journal ● Sep. 12, 2026

The company said products are moving through its distribution network at or above normal levels as the Marlborough, Mass., company works to fulfill customer orders, reduce backlogs and accelerate the delivery of products.

From The Wall Street Journal ● Sep. 11, 2026

At age 79, Mr. Adams remains fit and energetic, and despite 55 years in the Golden State one can’t mistake this native of Worcester, Mass., for anything but a New Englander.

From The Wall Street Journal ● Sep. 8, 2026

We went to the later Mass. But first we changed our clothes, even Papa, and washed our faces.

From "Purple Hibiscus" by Chimamanda Ngozi Adichie

He loved crime stories in which the culprit was the slippery masses.

From Los Angeles Times ● Sep. 16, 2026

On Martha’s Vineyard, “beach keys” are the ultimate status symbol, giving affluent property owners entry to secluded stretches of sand that are off-limits to the masses.

From The Wall Street Journal ● Sep. 3, 2026

Instead, researchers detected something unexpected at nearby masses.

From Science Daily ● Sep. 2, 2026

But the task is complicated by the fact that risks are dispersed across the Himalayas, while a 2015 earthquake destabilized many rock masses on the southern slopes, the embassy said.

From The Wall Street Journal ● Aug. 30, 2026

Her gaze went past him, out of the window to where the snow lay in heavy masses.

From "Murder on the Orient Express" by Agatha Christie

A day before that incident, hundreds of masked protesters massed in Dover, further east, briefly blocking access to the town's busy Channel port to demonstrate against migrant crossings.

From Barron's ● Sep. 11, 2026

Playing on the title, it opens with a big gospel organ and a massed chorus, before a handbrake turn into lip-smacking rap.

From BBC ● May 8, 2026

The brief “Target Practice” opens the LP with a jaunty acoustic guitar figure and Mr. Picton’s somewhat reedy voice, and then adds a string section and massed voices that ratchet up the density and volume.

From The Wall Street Journal ● Apr. 14, 2026

Last week, around 1,200 boats massed in two parallel lines further east of the January and December events and held their positions for about 30 hours, Wang said.

From Barron's ● Mar. 13, 2026

More than three quarters of the knights were there, massed together like a great steel fist.

From "A Game of Thrones" by George R.R. Martin

Tankers are already massing outside the Strait to fill up.

From MarketWatch ● Jun. 18, 2026

Thousands of Chinese fishing boats have been massing in geometric formations in the East China Sea, in coordinated actions that experts believe are part of Beijing's preparations for a potential regional crisis or conflict.

From Barron's ● Mar. 13, 2026

Then comes the mosquito-like whine of the incoming Russian drones, massing in their hundreds just above the clouds.

From BBC ● Nov. 16, 2025

One day in December, Nat notices gulls, crows, starlings and wrens massing menacingly overhead.

From The Wall Street Journal ● Oct. 24, 2025

For the moment it withdrew them, and brought up new forces, massing them about Cirith Gorgor for an avenging stroke.

From "The Return of the King" by J.R.R. Tolkien

Related Words

• crowd
• group
• horde
• lot
• lump
• majority
• mob
• number
• piece
• pile
• throng