Did you know?

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


 - definition

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 entries. Click on the T button in an entry to review the synonyms and related words for that meaning.

verb British English pronunciation: harden /ˈhɑː(r)d(ə)n/ 
Word Forms
present tense
present participlehardening
past tensehardened
past participlehardened
  1. 1
    [intransitive/transitive] to become hard or firm, or to make something hard or firm

    This additive hardens the cement in an hour.

    The bread will harden if you don't cover it.

  2. 2
    [transitive] mainly literary to make someone become less affected or upset by unpleasant things so that they show less kindness or sympathy to other people
    harden someone to something:

    Years of reporting on wars hardened them to human suffering.

  3. 3
    [intransitive/transitive] if you harden your attitude, or if it hardens, you refuse to change it

    Forsyth appeared to have hardened his line on (=his attitude towards) Europe.

derived word


noun [singular/uncountable]

She has hardening of the arteries.

a hardening of opinion against the treaty

dark pool

a method of financial trading in which share prices are hidden and not openly available to the public

BuzzWord Article

Word of the Day


a share of the profits of a company, paid once or twice a year to the people who own the...

Open Dictionary


to post a tweet, usually a negative one, that mentions a person without using the @ sign, so that they will not see the message on their Twitter feed …

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