- The definition of a fly-by-night is an unreliable person who is generally not known and who cannot be trusted.
An example of fly-by-night person is the description used for a salesman who promises the world but doesn't deliver.
- A fly-by-night is defined as an unreliable person who is generally not known and who cannot be trusted.
An example of a fly-by-night is a contractor who takes your money to produce your kitchen cabinets and then never produces them.
- Unreliable or unscrupulous, especially with regard to business dealings: “some fly-by-night startup that was halfway to shutting down” (Douglas Edwards).
- Of an impermanent or insubstantial nature: fly-by-night fashions in clothing.
- An unreliable or unscrupulous person.
- One, such as a company, that is short-lived and therefore unreliable.
- A creature which flies at night; a nocturnal flier or traveler.
- One who departs or flees at night in order to avoid creditors, law enforcement etc. (often used attributively).
- Do not give your credit card number to that fly-by-night operation.
- (idiomatic, derogatory) A person or business that appears and disappears rapidly, or gives an impression of transience.
- (idiomatic, derogatory) A traveling businessman or tradesman.
The phrase implies that the quality of work done or goods sold is shoddy enough that the person responsible must leave town under cover of darkness to evade angry customers, or sometimes legal authorities. The earliest use of the phrase is said to have been a reproach for women, signifying that she was a witch. The modern usage first appeared in 1823.