I. mass 1 W2 /mæs/ BrE AmE noun
[ Sense 1-2,5-6: Date: 1300-1400 ; Language: French ; Origin: masse , from Latin massa , from Greek maza ]
[ Sense 3-4: Date: 800-900 ; Language: Vulgar Latin ; Origin: missa 'sending away at the end of a religious service' , from Latin mittere 'to send' ]
1 . LARGE AMOUNT
a) [countable] a large amount of a substance which does not have a definite or regular shape:
The food had congealed into a sticky mass.
a high mass of rock
b) [countable usually singular] a large amount or quantity of something
a huge mass of data
c) masses of something British English informal a large amount of something, or a lot of people or things:
Masses of books covered every surface in the room.
2 . CROWD [singular] a large crowd
There was a mass of people around the club entrance.
The road was blocked by a solid mass of protesters.
3 . the masses all the ordinary people in society who do not have power or influence:
The trains provided cheap travel for the masses.
4 . the mass of people/the population/workers etc most of the people in a group or society SYN the majority :
The war is strongly supported by the mass of the population.
5 . CHURCH CEREMONY ( also Mass )
a) [uncountable and countable] the main ceremony in some Christian churches, especially the Roman Catholic Church, which celebrates the last meal that Jesus Christ ate:
What time do you go to mass?
morning/evening/midnight etc Mass
Will I see you at morning Mass?
say/celebrate Mass (=perform this ceremony as a priest) ⇨ ↑ High Mass
b) [countable] a piece of music written to be performed at the ceremony of mass:
Mozart’s Mass in C minor
6 . SCIENCE [uncountable] technical the amount of material in something:
The Sun makes up 99.9% of the mass of our solar system.
⇨ ↑ critical mass
II. mass 2 W3 BrE AmE adjective [only before noun]
involving or intended for a very large number of people:
a mass protest
weapons of mass destruction
the problem of mass unemployment
mass marketing/entertainment etc
a mass marketing campaign
Email has made mass mailings possible at the touch of a button.
III. mass 3 BrE AmE verb [intransitive and transitive]
to come together, or to make people or things come together, in a large group SYN gather
mass (something) behind/along/in etc something
Western reports say that troops have been massing in the region since December.
grey clouds massing behind the mountains
Both countries have massed troops along the border.