Did you know?

Click any word in a definition or example to find the entry for that word

mass - definition and synonyms


What are red words?

90% of the time, speakers of English use just 7,500 words in speech and writing. These words appear in red, and are graded with stars. One-star words are frequent, two-star words are more frequent, and three-star words are the most frequent.



The thesaurus of synonyms and related words is fully integrated into the dictionary. Click on the thesaurus category heading under the button in an entry to see the synonyms and related words for that meaning.

verb [intransitive] mass pronunciation in British English /mæs/
Word Forms
present tense
present participlemassing
past tensemassed
past participlemassed
  1. to come together and form a large group
    Troops are massing along the southern border.
    1. a.
      [transitive] to bring people together and make them form a large group
      More than 5,000 police were massed within two days.


a course of study which is much shorter than a university course and focuses on the skills you need for a job, especially computer-related skills

BuzzWord Article

Open Dictionary


an ancient Roman system of underfloor heating, used to heat houses with hot air; from the Latin 'hypocaustum'

add a word


A must for anyone with an interest in the changing face of language. The Macmillan Dictionary blog explores English as it is spoken around the world today.

global English and language change from our blog