noun Also fly-by-night·er.
Origin of fly-by-night
Examples from the Web for fly-by-night
Some of the groups have been around for decades, others are fly-by-night.
And not fly-by-night issues either, but stalwarts such as G.E., Citi, Google.
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|Holman Day
What gets me is, when you boil our two fly-by-night stories down, I've come here to be alone.Seven Keys to Baldpate|Earl Derr Biggers
She now knew where she was, but was nearly dying from the exhaustion of his fly-by-night expeditions.Crooked Trails|Frederic Remington
She certainly has acted like a fly-by-night up to this time.They of the High Trails|Hamlin Garland
He'll be out with a fly-by-night troupe afore the next month.Watch Yourself Go By|Al. G. Field
British Dictionary definitions for fly-by-night
noun Also: fly-by-nighter
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.
Culture definitions for fly-by-night
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.”