Liberal Dictionary English Dictionary
adjective
- not reliable or responsible, especially in business; untrustworthy: a fly-by-night operation.
- not lasting; brief; impermanent; transitory: a fly-by-night theater.
noun Also fly-by-night·er.
- 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.
adjective
- unreliable or untrustworthy, esp in finance
- brief; impermanent
noun Also: fly-by-nighter
- 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
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.”