to sail under false colours
Preserved but no longer current.
To act hypo- critically; to try to attain your object by appearing to be other than you are. The term is a nautical one, and refers to the practice of pirates approaching their unsuspecting prey with false colours at the mast.
Era: ca. 1898 (Victorian)
Sources & notes
Reproduced from Brewer’s Dictionary of Phrase and Fable (1898 edition, public domain; archive.org, retrieved 2026-07-31; OCR text, minor errors possible). Reflects the scholarship and attitudes of its era.
Common questions
What does “to sail under false colours” mean?
To act hypo- critically; to try to attain your object by appearing to be other than you are. The term is a nautical one, and refers to the practice of pirates approaching their unsuspecting prey with false colours at the mast.
Is “to sail under false colours” formal or informal?
No register label has been reviewed yet — treat it as neutral and check the usage notes above.