Green’s Dictionary of Slang

(US gay) a lesbian who dresses butch only at weekends.

1998

(ref. to 1950s–60s) R. Scott Rebecca’s Dict. of Queer Sl. 🌐 Saturday night butch — a term from the 1950s and 60s, when butch/femme was the norm in lesbian bars, this means that a person was not a real butch, but only dressed up as a butch on the weekends. Women who were always butch and couldn’t hide it looked down on these people as posers.

(US drugs) an occasional (perhaps literally weekly) use of narcotics.

1938		D. Maurer ‘Lang. of the Und. Narcotic Addict’ Pt 2 in Lang. Und. (1981).
1959		J.E. Schmidt Narcotics Lingo and Lore.
1972		R.A. Wilson Playboy’s Book of Forbidden Words 66: Chippy user [...] a person who uses cocaine very occasionally in order to avoid becoming addicted, which is also known as having a chippy habit or a coffee-and-cake habit or a Saturday-night habit.

(US) the temporary paralysis of the arm, esp. a weakness in the wrist, after it has rested on a hard edge for a long time, as during sleep following a bout of drinking.

1927		I.S. Wechsler Textbook Clinical Neurology (1947) III 249: The frequent occurrence of wrist drop in alcoholics who fall asleep and lean heavily on the arm has given rise to the common designation of ‘Saturday night palsy’ .
1937		C.L. Callender Surgical Anantomy 900: Prolonged pressure on the nerve also may harm it: for example, ‘Saturday night paralysis’ is sustained when an intoxicated man falls asleep with his arm hanging over the back of a bench.
1942		Medical Bull. 18-19 459: The "Saturday night paralysis" of the alcohol debauch.
1951		E. Paul Springtime in Paris xii. 216: Berthe was suffering from what is known in the United States as Saturday-night paralysis, …when drunken men go to sleep in gutters, with one arm across a sharp kerbstone [OED].
1960, 1975		Wentworth & Flexner DAS 443/2: See Appendix, Drunk. Saturday-night-itis n. Stiffness in one’s arm, owing to having held it in a horizontal position too long, while resting on the back of a couch, chair, or car seat around a girl’s shoulders.
1972		J. Symons Notes from Another Country 124: My condition was similar to that known as Saturday night paralysis, suffered by those who fall asleep when drunk with one arm hanging over the side of a chair.
2003		‘What makes our feet fall asleep’ on MSNBC News 🌐 In fact, ‘Saturday night palsy’ is a name given to a condition that results from permanent injuries incurred when someone has passed out in an awkward position and is sleeping too deeply to respond to the body’s signals to move.
2011		S. Orlean Saturday Night 100: There is even a condition doctors call ‘Saturday-night paralysis’ — nerve damage caused by sleeping too long in a strange position, which usually only happens to someone who is falling-down drunk.

(US) a small handgun.

1929		M.A. Gill Und. Sl. n.p.: Saturday night pistol, 25 automatic.
2003		M. Dean Rock ’n’ Roll Gold Rush 346/1: The poor wayfaring stranger Beatle [i.e. John Lennon] [...] was struck several times by a volley of any-kid-can-buy-’em bullets from a $29 Saturday night pistol.

(US) an enthusiastic smile.

1949

R. Chandler Little Sister 123: Miss Helen Grady gave me her Saturday night smile.

(US) a small handgun, often used in the many fracas that occur over Saturday night in big US cities.

1968		N.Y. Times 17 Aug. 1/1: Title IV of that law bans the importation of the cheap, small-caliber ‘Saturday night specials’ that are a favorite of holdup men.
1975		Sepe & Telano Cop Team 57: A ‘Saturday night special,’ a cheaply made, foreign .22-caliber revolver.
1989		J. Morton Lowspeak.
1991		D. Simon Homicide (1993) 537: The state’s vaunted Saturday Night Special law [...] to identify and prohibit the sale of cheap handguns.
2002		G.L. Carter Guns in Amer. Society 516/1: The term ‘Saturday night special’ was chosen in order to depict the gun as being used by some ne’er-do-well who might get drunk on a Saturday night and shoot it off randomly.
2008		R. Price Lush Life 273: A Saturday-night special, piece of shit probably would’ve blown off his hand if he pulled the trigger .
2023		A. Nette Orphan Road 92: ‘Ruger LCP, what we used to call a Saturday night special back in the day’.

see Monday morning quarterback n.