Green’s Dictionary of Slang

straight n.2

1. a conventional, respectable person, as opposed to a criminal.

[UK]‘Doss Chiderdoss’ ‘The Blokes Outside’ Sporting Times 6 Aug. 1/4: When I see the ‘crooks’ thought more of than the ‘straights,’ / I feel sorry for the blokes outside!
[US]C. Stroud Close Pursuit (1988) 41: The way the straights and the shits were mixed up over there, no sensible citizen would freely give a cop good information.
[UK]N. Cohn Yes We have No 145: A scattering of straights, seeking refuge.
[UK]Guardian Rev. 18 Mar. 3: How the boys in the back of the bus must have laughed at the straights.

2. conventional heterosexual intercourse in the face to-face ‘missionary position’; thus in prostitute’s use, straight date n., one who desires conventional intercourse; straight girl n., a prostitute who only offers such a service; also pornography featuring this.

[US] ‘Mme. Dora in “Strictly Business”’ [comic strip] in B. Adelman Tijuana Bibles (1997) 75: What do you want honey? Straight, French or any other?
[US]D. Maurer ‘Prostitutes and Criminal Argots’ in Lang. Und. (1981) 117/1: straight. Normal sexual intercourse; a straight date, a customer who wants normal intercourse; a straight girl, one who does not practice perversions.
[US] in S. Harris Hellhole 91: And she said, ‘Twenty bucks.’ And I said, ‘What do I get for that?’ And she said, ‘A straight or Frenchy if you want it.’.
[US]‘Heat Moon’ Blue Highways 191: I heard girls at the Big Four are getting twenty-five simoleons for a straight.
[UK](con. 1960s) A. Frewin London Blues 69: straight is a white couple doing it missionary style or side by side (but certainly not doggy style).

3. (orig. gay) a heterosexual person.

[US]Lavender Lex. n.p.: straight:– Any person other than a homosexual.
[US] in S. Harris Hellhole 222: Men in grey flannel suits who strive to look like straights but disclose themselves as what they are by [...] the flicking of a finger.
[US]A. Maupin Tales of the City (1984) 96: A couple of sherbet straights, doing a very showy Arthur Murray routine.
[US](con. 1940s) C. Bram Hold Tight (1990) 96: Two randy straights who could say it all to each other.
[Aus]R.G. Barrett Davo’s Little Something 23: You straights give me the shits.
Kennedy & Davies (con. 1940s-50s) Boots of Leather (2014) 7: The term ‘bull-dagger’ was used by hostile straights as an insult.
[UK]Guardian G2 16 Dec. 4: I’m too poofy for the poofs and too scary for the straights.

4. (also straight-head) used by members of the ‘counter-culture’ to describe a member of Establishment society.

[US]Newsweek 30 Oct. 85: For most straights, press reports of the East Village murders added a sinister new word to their glossary of hipisms.
[UK]Gandalf’s Garden 6 n.d. 11: straights: basically people, groups, organisations, etc. who confine themselves to an extremely limited view of the world and conception of themselves, under the impression that they are broadminded, but who have a straight-jacketed mentality, causing them to deride or disbelieve anything which is not projected by establishment manipulated media [...] Conformist, ‘square’, unfree, restricted for fear of others’ opinions.
[UK]G.F. Newman You Flash Bastard 64: A highly responsible member of a highly respected profession coming to try and corrupt the untouchable CID. He wondered fleetingly what the general public [...] who still had faith in the police, belief in the system, would make of it. What would they do without those straights? Without them it would all disintegrate.
[US]C. McFadden Serial 32: A superstraight with a button-down banker’s mind.
[UK]B. Hare Urban Grimshaw 222: Most straight-heads don’t understand what the drug culture is all about.

5. (US campus) one who stands outside the current social norms.

[US]Eble Sl. and Sociability 59: Three geometric terms – straight, square, and quad – are all derogatory epithets that designate with various connotations ‘a person who does not fit in with the prevailing college life style’.

In derivatives

In phrases

run off the straight (v.) [i.e. the ‘straight and narrow’]

to abandon a respectable life for criminality.

[UK] ‘’Arry on a Jury’ in Punch 15 Apr. 177/1: Oh, don’t be alarmed, dear old chummie, I aven’t bin run off the straight.