BOLD AS BRASS, adv. phr. (colloquial).—Audaciously forward; presumptuous; without shame. Shakespeare uses the expression ‘a face of brass’: see BRASS.

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  1594.  SHAKESPEARE, Love’s Labour’s Lost, v. 2.

          Biron.  Thus pour the stars down plagues for perjury.
Can any FACE OF BRASS hold longer out?——

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  1846.  THACKERAY, Vanity Fair, II., 12. He came in as BOLD AS BRASS.

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  1854.  THACKERAY, Lovel the Widdower, 195. ‘A nursery governess at the wages of a housemaid,’ I continued, as BOLD AS CORINTHIAN BRASS.

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  c. 1882.  Broadside Ballad, ‘Timothy Titus.’

        The name belongs to brave men, and
  I’m as BOLD AS BRASS.

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