a body of coherent matter, usually of indefinite shape and often of considerable size.
a mass of dough.
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.
a collection of incoherent particles, parts, or objects regarded as forming one body.
a mass of sand.
aggregate; whole (usually preceded byin the ).
People, in the mass, mean well.
a considerable assemblage, number, or quantity: a mass of troops.
a mass of errors;
a mass of troops.
bulk, size, expanse, or massiveness.
towers of great mass and strength.
Fine Arts.
Painting. an expanse of color or tone that defines form or shape in general outline rather than in detail.
a shape or three-dimensional volume that has or gives the illusion of having weight, density, and bulk.
the main body, bulk, or greater part of anything.
the great mass of American films.
Physics. the quantity of matter as determined from its weight or from Newton's second law of motion. m
Pharmacology. a preparation of thick, pasty consistency, from which pills are made.
the masses, the ordinary or common people as a whole; the working classes or the lower social classes.
pertaining to, involving, or affecting a large number of people.
mass unemployment;
mass migrations.
affecting a number of people, but more than two and typically a large number: a mass shooting.
mass murder;
a mass shooting.
participated in or performed by a large number of people, especially together in a group: mass suicide.
mass demonstrations;
mass suicide.
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.
reaching or designed to reach a large number of people.
television, newspapers, and other means of mass communication.
done on a large scale or in large quantities.
mass destruction.
the celebration of the Eucharist.
(sometimes lowercase) a musical setting of certain parts of this service, as the Kyrie eleison, Gloria, Credo, Sanctus, Benedictus, and Agnus Dei.
a large coherent body of matter without a definite shape
a collection of the component parts of something
a large amount or number, such as a great body of people
the main part or majority
the mass of the people voted against the government's policy
in the main; collectively
the size of a body; bulk
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
(in painting, drawing, etc) an area of unified colour, shade, or intensity, usually denoting a solid form or plane
pharmacol a pastelike composition of drugs from which pills are made
mining an irregular deposit of ore not occurring in veins
done or occurring on a large scale
mass hysteria
mass radiography
consisting of a mass or large number, esp of people
a mass meeting
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.
See Note at weight See also rest energy General Relativity
See size 1.
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.
First recorded in 1350–1400; Middle English masse, from Latin massa “mass,” from Greek mâza “barley cake,” akin to mássein “to knead”
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”
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.
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Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
The border crossing was calm, and groups of workers picked up trash, clothes and rubbish left behind during the mass crossing.
From Barron's ● Aug. 2, 2026
Evaristo Casares Fernandez, a sanitation worker, noted that it would fall to him to clean up the floating mass of footwear.
From The Wall Street Journal ● Aug. 2, 2026
Several fires have broken out in Greece this week, prompting mass evacuations.
From BBC ● Aug. 2, 2026
The UN has repeatedly warned that RSF advances in El-Obeid and the wider Kordofan region could lead to mass atrocities.
From Barron's ● Aug. 2, 2026
The mass of fire retardant wasn’t just going to hit the fire—it was going to hit the bald too.
From "Two Degrees" by Alan Gratz
Mass or individual culls are generally restricted to notifiable disease control, welfare emergencies, or licensed slaughter.
From BBC ● Jul. 30, 2026
A Mass for the men was held at sea a few days later.
From Los Angeles Times ● Jul. 20, 2026
Mass spectrometry allows scientists to measure the mass of molecules with exceptional precision.
From Science Daily ● Jul. 15, 2026
He said Mass at our reunion, and classmates of all denominations attended and were inspired by his homily.
From The Wall Street Journal ● Jul. 8, 2026
“You are eating ten minutes before Mass? Ten minutes before Mass?”
From "Purple Hibiscus" by Chimamanda Ngozi Adichie
For the current third quarter, the Marlborough, Mass., company projects revenue will increase 3% to 5%, with adjusted earnings per share estimated at 80 cents to 82 cents.
From The Wall Street Journal ● Jul. 29, 2026
For Luke Delorme, a certified financial planner in Great Barrington, Mass., AI is especially valuable in capturing and retaining client information.
From MarketWatch ● Jul. 24, 2026
Kathy L. McNair, author of “The Solo Senior’s Guide to Thrive” and an estate-planning attorney in Belmont, Mass., sees this happen frequently among retirees.
From MarketWatch ● Jul. 12, 2026
The ferry crossing from Chappaquiddick to Edgartown, Mass., is only 527 feet long.
From The Wall Street Journal ● Jul. 10, 2026
We walked halfway to Ballilee to the church for Mass. It took longer than usual.
From "Nory Ryan’s Song" by Patricia Reilly Giff
I never begrudge anyone who is a millionaire or billionaire his money—he or she has developed vital products for the masses.
From The Wall Street Journal ● Aug. 2, 2026
After 20 minutes, they found a spot — and joined the masses.
From Los Angeles Times ● Jul. 21, 2026
Judging from the amount of lithium detected in TOI-5882, the researchers estimate that the swallowed planet may have been somewhere between a couple of Earth masses and the mass of Neptune.
From Science Daily ● Jul. 16, 2026
Whether it be sport, music, or religion, the Azteca is built for moments when masses of people come together to feel alive.
From BBC ● Jul. 5, 2026
“John! Natalie!” the voice repeated, and I turned to see Mikayla’s mom, shouldering her way through the masses, eyes trained on me.
From "The Science of Breakable Things" by Tae Keller
Tens of thousands of demonstrators massed in central Belgrade Saturday to renew calls for early elections that grew out of the anti-corruption movement sparked by a deadly rail station disaster.
From Barron's ● May 23, 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
He has also massed 25,000 soldiers near Colombia, a likely vector for infiltration.
From Salon ● Nov. 3, 2025
“Bedstraw,” she said, pointing to a tall plant massed with golden blossoms.
From "Gathering Blue" by Lois Lowry
Tankers are already massing outside the Strait to fill up.
From MarketWatch ● Jun. 18, 2026
Mr. Bernthal, an Emmy winner for “The Bear,” imbues Sonny with a pinballing energy as he gabbles orders at the hostages and begins flailing negotiations with the cops massing outside.
From The Wall Street Journal ● Mar. 31, 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
Video posted to social media showed crowds massing at the Sheikh Radwan Cemetery for the journalists’ funeral.
From Los Angeles Times ● Aug. 11, 2025
The clouds above her were massing more and more ominously.
From "Inkheart" by Cornelia Funke
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.
