Green’s Dictionary of Slang

rail n.

1. (US tramp) an employee of a railroad.

[US] ‘Jargon of the Und.’ in DN V 460: Rail, A railway detective.
[US]V.W. Saul ‘Vocab. of Bums’ in AS IV:5 343: Rail—A railroad man.
[US]Monteleone Criminal Sl. (rev. edn).
[US]Ragen & Finston World’s Toughest Prison 814: rail – A railroad worker.

2. (US black) ? an automobile.

[US]Ted Yates This Is New York 11 Oct. [synd. col.] ‘Joe Louis [...] latched himself some rails and showed all Detroit that ‘tin’ can be turned into gold .

3. (US) an erection; thus get a rail on, to get an erection.

[US]San Diego Sailor 9: I had a bitch of a rail on and I couldn’t have got it back in my shorts. [Ibid.] 38: I surprised myself by getting a rail on almost immediately.

4. (US drugs) a thin line of a powdered narcotic [such lines tend to be cut in a parallel pair, one per nostril].

[US](con. 1975–6) E. Little Steel Toes 156: Taking turns buying rounds and cutting up rails of coke and speed.
[US]T. Dorsey Atomic Lobster 218: Rachel [...] dumped a generous pile of white powder and began cutting rails with a razor balde.
[UK]J.J. Connolly Viva La Madness 299: He’s pouring dangerous rails of cha-cha onto the table.
[US] M. McBride Frank Sinatra in a Blender [ebook] He did his rail first, the longest one, of course, which ran a good six inches.
[Scot]I. Welsh Decent Ride 116: It’s aw shaggin, cleanin oot the minbar, daein some rails, then repeatin.

SE in slang uses

In compounds

rail party (n.)

‘riding out of town on a rail’, i.e. punishing an unpopular target by tying them to a fence-rail and carrying them out of town; the victim is often also tarred-and-feathered.

[US]Nat. Police Gaz. (NY) 1 Feb. 7/2: A rail-party, in which the tar-and-feather sociable was omitted, because of the failure of that commitee to make the proper preparations, waa held in Hooketown, Beaver county. Pa., recently.

In phrases

off the rails [railway imagery]

1. emotionally stressed; usu. in phr., go off the rails.

G.E. Jewsbury Letter Mar. (1892) 242: I was very worried, and I felt as if the least thing would throw me off the rails .
[UK]‘Bartimeus’ ‘A Flower of the Sea’ in Seaways 259: Directly she goes away he goes clean off the rails.
[UK]D.L. Sayers Nine Tailors (1984) 177: It’s very rare for one of them sort of smart burglars to go all off the rails and take to violence.
[UK]‘Charles Raven’ Und. Nights 202: A former sky-pilot who had come off the rails.
[UK]G. Lambert Inside Daisy Clover (1966) 158: I wondered if [...] she always went off the rails when a stud left her.
[UK]T. Blacker Fixx 40: Members of the fair sex frequently go off the rails at the point sublime.
[UK]Indep. on Sun. 10 Oct. 11: Locked up for days on end [...] it’s little wonder that inmates sometimes go off the rails.
[UK]Indep. on Sun. Rev. 23 Jan. 54: She plays Iris, a young woman who goes off the rails when her mother [...] dies.
[US]N.Y. Times 27 June n.p.: Earlier technological developments left their mark on the language. The railroads gave rise to expressions like ‘going off the rails’ and ‘getting sidetracked’; the steam engine produced ‘working up a head of steam’ and ‘full steam ahead’.
[Aus]L. Redhead Rubdown [ebook] It’s my daughter Tamara. She’s gone off the rails.
[Ire]Breen & Conlon Hitmen 114: John was not the only one going off the rails.

2. errant, mistaken, esp. in phr. go off the rails, to blunder, to make a mistake.

[UK] ‘’Arry on Fashion’ in Punch 10 Sept. 110/1: Brown nicer, becominger, cheaper? Ah, that’s where you’re right off the rails. / It’s Fashion they want, and not fitness.
[UK]J. Ware Passing Eng. of the Victorian Era 186/1: Off the rails (line) (Peoples’, 1840 on). Unsteady.
[UK]Hull Dly Mail 2 Nov. 4/5: She ain’t off the rails by a blinkin’ long chalk.
[UK]S. Scott Human Side of Crook and Convict Life vii: It [i.e. a book] sets forth the human aspects of the man and woman who have ‘gone off the rails’.
[UK]Wodehouse Right Ho, Jeeves 36: Jeeves, who, however much he go off the rails in the matter of dress clothes [...] has always had a neat turn of phrase.
[UK]F. Norman Bang To Rights 46: I am only trying to find out what was the cause of you going off the rails again.
[NZ]G. Slatter Pagan Game (1969) 220: No wonder some of them run off the rails sometimes. They just do it to nark the big nanas.
[UK](con. 1940s) O. Manning Battle Lost and Won 337: You know you can trust Guy. He’s not the sort to go off the rails.
[UK]G. Young Slow Boats to China (1983) 381: I wondered if [...] there was much infidelity and ‘going off the rails’.
[UK]Guardian G2 25 Mar. 7: He is also worried about Shaun’s siblings who could go off the rails.

3. to exceed or defy social norms.

Halifax Courier 23 Dec. 6/4: The gap between 14 and 16 [...] Those two years [...] when it was easy either to go forward to something real or easy to go off the rails.
[UK]Bury Free Press 28 Jan. 8/2: Youngsters who go off the rails. Juvenile delinquency, they say, is caused by gangster films [...] What rubbish!
[US](con. 1991-94) W. Boyle City of Margins 107: ‘I’ve got a guy off the rails [...] He’s going around saying, ‘Fuck Big Time Tommy. I’m not paying that tubby bitch’.

4. exceptional.

‘Ace & Invisible’ on 1Xtra 28 Apr. [BBC radio] That track is absolutely off the rails.