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serious

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adjective serious pronunciation in British English /ˈsɪəriəs/
  1. 1
    bad or dangerous enough to make you worried

    The sale of the company will have serious implications for people's jobs.

    a serious problem/mistake:

    It's not a serious problem – we should be able to fix it without too much trouble.

    a serious illness/accident/injury:

    a serious head injury

    a serious crime/offence/threat:

    An accident like this poses a serious threat to the environment.

    Synonyms and related words for this sense of serious
    Synonyms and related words for this sense of serious
    Synonyms and related words for this sense of serious
  2. 2
    important and deserving attention

    This is an extremely serious matter.

    He has no serious competition for the post.

    Synonyms and related words for this sense of serious
  3. 3
    meaning what you say or do, and not making a joke

    I'm sorry, I didn't realize you were being serious.

    The police have made no serious attempt to address these issues.

    serious about:

    I'm not convinced they're serious about the deal.

    serious about (doing) something:

    Do you think Mike's serious about going to live in New Zealand?

    deadly/dead (=completely) serious:

    'Are you serious about leaving your job?' 'Dead serious.'

    Synonyms and related words for this sense of serious
  4. 4
    careful and detailed
    serious consideration/thought/discussion:

    We'll have to give the situation some serious thought.

  5. 5
    someone who is serious thinks carefully about things and does not laugh much

    Peter seems serious but he actually has a good sense of humour.

    Synonyms and related words for this sense of serious
    1. a.
      appearing worried or upset

      Is Mary all right? She looked a bit serious.

      Synonyms and related words for this sense of serious
  6. 6
    [usually before noun] dealing with important, complicated, or difficult ideas or subjects

    serious books/music

    Synonyms and related words for this sense of serious
  7. 7
    if you are in a serious romantic relationship with someone, you intend to stay together for a long time

    Is it getting serious with you and June, then?

    a serious boyfriend/girlfriend/relationship:

    He's never had a serious relationship with anyone.

  8. 9
    informal extreme, or large in amount

    We did some serious hiking last weekend.

    It's time you made some serious money.

phrases

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seriousness

 serious pronunciation in British English  noun [uncountable]

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