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.
This summer’s Northern Hemisphere heat wave has been a mass casualty event, on a par with the recent earthquakes in Venezuela.
From Salon ● Jul. 19, 2026
Her reorientation of the division led to a mass exodus of career staff — nearly three-quarters of the roughly 400 attorneys who were there at the beginning of 2025, by Dhillon’s telling.
From Los Angeles Times ● Jul. 19, 2026
Easwar pointed to the challenges posed by mass events such as the Kumbh Mela pilgrimage, where millions of devotees gather and large volumes of offerings are collected.
From Barron's ● Jul. 19, 2026
Researchers measured body weight, fat mass, and fat free mass before and after the intervention.
From Science Daily ● Jul. 18, 2026
All together, the cortex is a soft mass of folded nerve tissue.
From "Phineas Gage" by John Fleischman
Mass spectrometry allows scientists to measure the mass of molecules with exceptional precision.
From Science Daily ● Jul. 15, 2026
The ballot measure from Boston-based Mass Opportunity Alliance, a coalition of pro-growth business groups, proposed to lower the state’s 5% income-tax rate to 4% by 2029.
From The Wall Street Journal ● Jul. 5, 2026
The group, known as SSPX, claims hundreds of thousands of followers and opposes many of the modernizing changes the Catholic Church adopted in the 1960s, including the end of the Latin Mass.
From The Wall Street Journal ● Jul. 2, 2026
The Society rejects key modernising reforms introduced by the Vatican in the 1960s and 1970s, including permission to hold Mass in languages spoken by the congregation, rather than only in Latin.
From BBC ● Jul. 1, 2026
Aunty Ifeoma said they had gone to the early Mass and they would see us at lunchtime.
From "Purple Hibiscus" by Chimamanda Ngozi Adichie
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
However, Jonathan White, trusts and estates partner with Jordan & White in Danvers, Mass., says it’s better to get your wishes in writing, even if it’s just for the caregiver’s peace of mind.
From The Wall Street Journal ● Jul. 3, 2026
It’s also where his father and two brothers went, while his sister earned her doctorate from that other school in Cambridge, Mass., known as MIT.
From The Wall Street Journal ● Jun. 25, 2026
“People stop going to stores, to Sunday Mass. They limit doctors appointments,” Goodman said.
From Los Angeles Times ● Jun. 14, 2026
The mermaids were dancing and singing in Latin like the priests do at the cathedral during Mass. You were there with me too, at the bottom of the sea.
From "Krik? Krak!" by Edwidge Danticat
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
Their masses typically range from several times the mass of the Sun to billions of solar masses.
From Science Daily ● Jul. 3, 2026
The more the traditional studios get taken over and reimagined by the tech world, the fewer stories we’ll see greenlit and created for the masses.
From Slate ● Jul. 2, 2026
His short on Elon Musk’s electric-vehicle maker, which is racing to bring autonomous driving to the masses, was noted with a price target of $416.22.
From The Wall Street Journal ● Jul. 1, 2026
We sit through an overly sentimental video about "huddled masses" and listen to a bulky soprano belt out the words to "My Country, 'Tis of Thee."
From "You Bring the Distant Near" by Mitali Perkins
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
Tens of thousands of allied troops were massed on Iraq and Kuwait's borders for the ground war, which was still nine days away.
From BBC ● Mar. 11, 2026
He has also massed 25,000 soldiers near Colombia, a likely vector for infiltration.
From Salon ● Nov. 3, 2025
He saw a lone warrior standing on a stone bridge, facing an entire army massed on the far side of the Tiber River.
From "The House of Hades" by Rick Riordan
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
He adapted their simple massing and abstract play of volumes, graced them with a few flourishes of Colonial detail, and served them up to young clients on Long Island and in coastal Massachusetts.
From The Wall Street Journal ● Nov. 28, 2025
Border Patrol agents were massing nearby, creating a show of force outside the event.
From Los Angeles Times ● Sep. 20, 2025
And while Americans were still digesting these worrisome assessments, out of the Middle East came the first sketchy reports of Egyptian troops massing on the Israeli border.
From "The Best of Enemies" by Osha Gray Davidson
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.
