- not reliable or responsible, especially in business; untrustworthy: a fly-by-night operation.
- not lasting; brief; impermanent; transitory: a fly-by-night theater.
- a person or thing that is unreliable, especially a debtor who evades or attempts to evade creditors.
- a person regarded as a poor credit risk.
Origin of fly-by-night
Examples from the Web for fly-by-night
She certainly has acted like a fly-by-night up to this time.They of the High Trails
He'll be out with a fly-by-night troupe afore the next month.Watch Yourself Go By
Al. G. Field
Shown up in our newspapers as a ditch-digger—a fly-by-night—a nobody!The Landloper
Had the wind been directly astern, the course of the Fly-by-Night would have been smoother.Janice Day
Helen Beecher Long
Torched on by that fly-by-night who'll be getting out of town and who'll be forgotten inside a week.When Egypt Went Broke
- unreliable or untrustworthy, esp in finance
- brief; impermanent
- an untrustworthy person, esp one who departs secretly or by night to avoid paying debts
- a person who goes out at night to places of entertainment
Word Origin and History for fly-by-night
1796, slang, said to be an old term of reproach to a woman signifying that she was a witch; extended 1823 to "anyone who departs hastily from a recent activity," especially while owing money. The two senses involve the two verbs fly.
Shady or untrustworthy: “Before buying stock in a newly formed company, the prudent investor will check its owners' credentials to make sure it's not a fly-by-night operation.”