blue o'clock

noun

A time very early in the morning, just before dawn.

First used 19th c.
Ask AI about this wordChatGPTClaudePerplexityGoogle AIGrok

Meanings

nounblue o'clock (uncountable)
  1. colloquialuncountableA time very early in the morning, just before dawn.First known use 19th c.

    All of us girls, Marjorie Tombey, Marion, Alyse and I in our chassis, dipping in the swanny at blue o'clock.

    1947, Robert Briffault, New Life of Mr Martin, page 121
    1 more example

    We had a midnight lunch too after all the jollification and when we sallied forth it was blue o'clock the morning after the night before.

    1922 February 2, James Joyce, “[Episode 10: Wandering Rocks]”, in Ulysses, Paris: Shakespeare and Company […], →OCLC, part II [Odyssey], page 225
Cite this entry
APA

blue o'clock. (n.d.). In WatkinsX Dictionary. Retrieved November 4, 2026, from https://dictionary.watkinsx.com/word/blue%20o'clock

MLA

“blue o'clock.” WatkinsX Dictionary, https://dictionary.watkinsx.com/word/blue%20o'clock. Accessed November 4, 2026.

Chicago

WatkinsX Dictionary, s.v. “blue o'clock,” accessed November 4, 2026, https://dictionary.watkinsx.com/word/blue%20o'clock.

Source: blue o'clock on Wiktionary, CC BY-SA 4.0.