Green’s Dictionary of Slang

1. (also fly-by-nighter) one who defrauds the landlord by leaving his lodgings in the middle of the night, having failed to pay the rent.

1823		‘Jon Bee’ Dict. of the Turf, the Ring, the Chase, etc. 81: Fly-by-night — run-aways who leave empty houses.
1894		Truth (Sydney) 23 Dec. 1/4: Flash Phil, a ten-stone fly-by-night, ordered him to shut up.
1924		H.L. Wilson Professor How Could You! 188: Mrs. Gale rather looked down upon her neighbors, calling them fly-by-nights.
1981		J. Ellroy Brown’s Requiem 120: ‘Do you know where I can find him?’ ‘Naw, he’s just a bum. A fly-by-night.’.
1991		(con. 1920s) O.D. Brooks Legs 118: She was making up for a few of the many times she’d been beaten out of a week’s rent by fly-by-nights.

2. a sedan chair on wheels.

1937–84

Partridge DSUE (1984) 412/2: the Regency.

3. (US) a small touring theatrical company.

1887

Daily Trib. (Bismarck, ND) 23 Oct. 4/1: Small companies in the back country districts are ‘fly by nights,’ ‘water tank shows,’ ‘Jim Crows,’ ‘crossroad concerns’ or ‘barn stormers.’.

4. (also fly-by-nighter) anyone dubious, crooked, criminal, esp. of a businessman who takes one’s money but fails to provide any or at least adequate recompense.

1922		S. Lewis Babbitt (1974) 39: A thing called Ethics, whose nature was confusing but if you had it you were a High-class Realtor and if you hadn’t you were a shyster, a piker, and a fly-by-night.
1931		O. Strange Law O’ The Lariat 118: What with the girl, Bart, an’ these fly-by-nights, I’m ’bout as welcome as a wet dawg in this neck o’ the woods.
1939		‘Flann O’Brien’ At Swim-Two-Birds 75: Get back to hell to your prairies, says he, you pack of lousers who can be taken in by any fly-be-night with a fine story.
1943		‘Myles na gCopaleen’ Faustus Kelly in ‘Flann O’Brien’ Stories & Plays (1973) 136: What are you bleating and blathering about, you Cork fly-by-night, bleeding and besting the ratepayers to the tune of four hundred and fifty pounds a year.
1947		Yorks. Eve. Post 2 jan. 5/3: Smugglers [...] Rip-roaring fly-by-nights.
1848		‘Ned Buntline’ Mysteries & Miseries of NY 160: ‘So that’s who you are! [...] A couple of sneaking fly-by-nights’.
1965		J. Thompson Texas by the Tail (1994) 12: No fly-by-nights, sir. Just a plain old-fashioned American family.
1984		P. Corris ‘Heroin Annie’ in Heroin Annie [e-book] You know, Doc [...] you shouldn’t deal with fly-by-nighters like this. Could get you into trouble.
1989		M. Amis London Fields 50: Keith as fly-by-night, as man with no name.
2000		G.V. Higgins At End of Day (2001) 47: Thirty years later, still fly-by-nighters, sellin’ TVs off the back of trucks [...] one day, hijacking a load of dry goods in Connecticut the next.

5. (UK Und.) itinerant casinos, moving every night to avoid the detection of illegal gambling.

1920		Dundee Courier 3 Mar. 5/6: Police raid on the ‘Fly-by-Night’ Club [...] They played at various addresses in the West End, [...] usually made known to [players] only about half an hour beforehand .
1938		F.D. Sharpe Sharpe of the Flying Squad 322: The system of ‘fly by nights’ was introduced; gaming taking place by arrangement at a different address each night.

6. (N.Z. prison) a very short sentence, it ‘flies by’.

2001

D. Looser Boobslang [U. Canterbury D.Phil. thesis] 72/1: fly-by-night n. 1 = fly-by lag.