| 1. | a body of coherent matter, usually of indefinite shape and often of considerable size: a mass of dough. |
| 2. | a collection of incoherent particles, parts, or objects regarded as forming one body: a mass of sand. |
| 3. | aggregate; whole (usually prec. by in the): People, in the mass, mean well. |
| 4. | a considerable assemblage, number, or quantity: a mass of errors; a mass of troops. |
| 5. | bulk, size, expanse, or massiveness: towers of great mass and strength. |
| 6. | Fine Arts.
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| 7. | the main body, bulk, or greater part of anything: the great mass of American films. |
| 8. | Physics. the quantity of matter as determined from its weight or from Newton's second law of motion. Abbreviation: m Compare weight (def. 2), relativistic mass, rest mass. |
| 9. | Pharmacology. a preparation of thick, pasty consistency, from which pills are made. |
| 10. | the masses, the ordinary or common people as a whole; the working classes or the lower social classes. |
| 11. | pertaining to, involving, or affecting a large number of people: mass unemployment; mass migrations; mass murder. |
| 12. | participated in or performed by a large number of people, esp. together in a group: mass demonstrations; mass suicide. |
| 13. | pertaining to, involving, or characteristic of the mass of the people: the mass mind; a movie designed to appeal to a mass audience. |
| 14. | reaching or designed to reach a large number of people: television, newspapers, and other means of mass communication. |
| 15. | done on a large scale or in large quantities: mass destruction. |
| 16. | to come together in or form a mass or masses: The clouds are massing in the west. |
| 17. | to gather into or dispose in a mass or masses; assemble: The houses are massed in blocks. |

The common name in the Roman Catholic Church, and among some members of the Anglican Communion, for the sacrament of Communion.
Note: 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.
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.
Note: 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 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.)
mass (mās)
n.
A unified body of matter with no specific shape.
A grouping of individual parts or elements that compose a unified body of unspecified size or quantity.
The physical volume or bulk of a solid body.
Abbr. m The measure of the quantity of matter that a body or an object contains. The mass of the body is not dependent on gravity and therefore is different from but proportional to its weight.
A thick, pasty pharmacological mixture containing drugs from which pills are formed.
One of the seven fundamental SI units, the kilogram.
See massa.
| mass (mās) Pronunciation Key
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. |