What does ‘a bolt from the blue’ mean?

To “a bolt from the blue” means to a sudden, unexpected event. The phrase is popularly linked to Thomas Carlyle's writings in the 19th century; the image is of lightning from a clear sky.

Origin

  • The phrase is popularly linked to Thomas Carlyle's writings in the 19th century; the image is of lightning from a clear sky.

How to use it

  • Common in describing shocking news.
  • Example: Her resignation was a bolt from the blue.

Source:

Last verified: 2026-07-18

  • Definitions and origins are drawn from public-domain reference works, primarily Brewer's Dictionary of Phrase and Fable (1898), with modern usage notes clearly marked.

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