blue flag
Preserved but no longer current.
Meaning · English
He has hoisted the blue flag; he has commenced publican, or taken a public house, an allusion to the blue aprons worn by publicans. See ADMIRAL OF THE BLUE.
Era: ca. 1811 (Georgian)
Where it’s used:
Origin
British & Irish English
Sources & notes
Historical definition reproduced from Grose’s Dictionary of the Vulgar Tongue (1811 edition, public domain; Project Gutenberg #5402, retrieved 2026-07-31). Reflects the attitudes of its era.
Common questions
What does “blue flag” mean?
He has hoisted the blue flag; he has commenced publican, or taken a public house, an allusion to the blue aprons worn by publicans. See ADMIRAL OF THE BLUE.
Is “blue flag” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.