E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
Flags Down (The).
Indicative of distress. When the face is pale the flag is down. Alluding to the ancient custom of taking down the flag of theatres during Lent, when the theatres were closed.
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Tis Lent in your cheeks, the flags down.Dodsleys Old Plays (vol. v. p. 314, article, Mad World.)