Definition of (as) thick as thieves in English:

(as) thick as thieves

phrase

informal
  • (of two or more people) very close or friendly.

    ‘he and Auntie Lou were thick as thieves’
    • ‘They lost interest in each other during the teenage years - by then it was all about rivalry - but now, as mothers themselves, they're as thick as thieves again.’
    • ‘‘He was seven years older than I, but even then, we were inseparable, thick as thieves,’ she said with a soft laugh.’
    • ‘We were as thick as thieves and would share any secret with one another.’
    • ‘‘By the end, we were all thick as thieves,’ insists McCann.’
    • ‘Besides, I thought you two were as thick as thieves.’
    • ‘I was in love with her, and for two years the two of us were thick as thieves.’
    • ‘In the olden days, Bryan and Justin had been as thick as thieves, closer than brothers, best friends for life.’
    • ‘I can't remember how our friendship really got going, but before we knew it we were thick as thieves.’
    • ‘The younger girl is drawn to Anita's rebellious streak and they soon become thick as thieves.’
    • ‘No wonder she and Claire were the best of friends and thick as thieves.’
    friendly, intimate, familiar, on friendly terms, on good terms, on the best of terms, hand in glove
    View synonyms