Green’s Dictionary of Slang

1. (US) honest, e.g. a one-way guy, an honest man; thus a two-way guy, a crook.

1930		J. Lait Put on the Spot 110: A decent citizen was a one-way sucker; a law breaker was two-way worker.
1935		A.J. Pollock Und. Speaks n.p.: One way moniker, true name of person.
1939		Howsley Argot: Dict. of Und. Sl. 35: one way guy – an honest individual who can’t be influenced or bribed.
1949		Monteleone Criminal Sl. (rev. edn) 168: one way egg [...] one way guy An honest person.

2. (US) narrow- or close-minded; obsessive; self-interested.

1953		L. Uris Battle Cry (1964) 136: He’s getting awful one-way.
1960		(con. WWII) R. Leckie Marines! 75: You can’t make me believe that that Captain Boort’s anything but a one-way paper-ass.
1972		B. Rodgers Queens’ Vernacular 144: one-way baby [Charley, man, stud] [...] 2. one who insists upon doing it his way; everything’s on his terms.
1978		J. Webb Fields of Fire (1980) 146: Don’t be such a one-way dude, Phony. You cain’ do ever’body, man.
1985		T.R. Houser Central Sl. 39: one-way Out for oneself [...] ‘Where’s my shit in this, man, you one-way’.

3. (US gay) heterosexual.

1966

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