Meaning
Describes a person or business that is unreliable because it may disappear overnight, especially to avoid paying rent, wages or other debts; also used as a noun for such a person. The phrase carries a strong suggestion of shady, short-lived commercial dealings rather than mere misfortune. Informal and strongly disapproving; normally hyphenated (fly-by-night) when used before a noun. Regional use: General English.
Origin
The earliest records make it an insult meaning witch, not a label for runaway debtors. Francis Grose's Classical Dictionary of the Vulgar Tongue (1788) glosses fly-by-night as an ancient term of reproach for an old woman supposedly a witch, alluding to the night flights on broomsticks credited to witches, and Etymonline cites a 1793 German-English dictionary for the same slur. The sense shifted to people who vanish while owing money, which Etymonline dates to 1823, and the 'fly-by-night company' idea of a shady, short-lived business followed during the 19th century. The often-repeated story that the phrase began as a pejorative for itinerant tradesmen fleeing creditors at night in fact describes this later debtor sense, not the documented origin; no source records how the meaning moved from witch insult to absconding debtor.
Research Sources
References used to check this entry’s meaning, history, or documented forms.
Variants
- fly-by-night company
- fly-by-night merchant
- fly-by-night operator
- fly-by-night outfit
- fly-by-night trader
Usage Examples
- The warranty is worthless if the installer turns out to be some fly-by-night outfit that vanishes after the first hard winter.
- Regulators warned that fly-by-night operators were taking deposits for building work and then disappearing before a single brick was laid.
- She checked the letting agent's registration carefully, having been cheated by a fly-by-night landlord in her first year in the city.