Green’s Dictionary of Slang

1. morally and legally unconstrained; the assumption being that the authorities are paid off).

1872		‘Mark Twain’ Roughing It 303: There were [...] hotels, theatres, ‘hurdy-gurdy houses,’ wide-open gambling palaces [etc.].
1899		H.E. Hamblen Yarn of Bucko Mate 105: In those days Callao was ‘wide open’ day and night.
1903		O. Kildare My Mamie Rose 70: A number of dance-halls [...] completed the boast of the day that New York City was a ‘wide-open town,’ and the ‘only place in the world fit to live in.’.
1909		W. Irwin Confessions of a Con Man 41: As wide-open as a saloon door and as crooked as a corkscrew.
1912		Ade Knocking the Neighbors 178: Steve roamed the Wide-Open Town and spread his Bets.
1913		H.A. Franck Zone Policeman 88 82: It is distinctly unlawful to sell liquor on Sunday or to gamble at any time on the Canal Zone; it is therefore with something approaching a shock that one finds everything ‘wide open’ and raging just across the street.
1926		(con. 1860s) F.J. Wilstach Wild Bill Hickok 118: Springfield at the time, we gather [...] was what would be called a ‘wide-open’ burg.
1931		Ade Old-Time Saloon 12: I knew Chicago so well during the rampageous wide-open period.
1946		Mezzrow & Wolfe Really the Blues 90: In ’26 Detroit was as wide open as a politician’s pocket on election day.
1949		Sun. World-Herald Mag. (Omaha, NE 12 June 4/1: In the field of municipal government, a myth has been developed and sustained in many cities that a wide-open town policy is good business [DA].
1956		H. Whittington Forgive Me, Killer (2000) 91: The vice, the gambling, the corruption. This is a wide-open town, Lieutenant. Vicious —.
1961		‘Lou Rand’ Gay Detective (2003) 60: This town used to be wide open. It was the talk of the world.
1967		G. Legman Fake Revolt 24: Puerto Rico, Hamburg, or Las Vegas, or some other gook country where prostitution and drugs are wide-open.
1977		G. Melly Rum, Bum and Concertina (1978) 37: Leeds, a wide-open city with enough tarts and drunkenness to earn itself one of those ‘revealing’ articles in the News of the World.
1996		(con. 1948) G. Pelecanos Big Blowdown (1999) 105: Everything as loose, wide-open, different from what the hard-working mill workers [...] were used to.
2012		W. Keyser ‘Carny Lingo’ in http://goodmagic.com 🌐 Wide Open — A show or carnival where ‘anything goes’: the girl shows can play as ‘strong’ as they want and the games can take the marks for as much as they can get.

2. vulnerable, undefended.

1928		C. McKay Home to Harlem 287: You kain’t lay you’self wide open lak thataways in this heah burg.
1931		(con. 1910s) C.W. Willemse Behind The Green Lights 159: He had a letter in his pocket advising him to come there when things were wide open.
1948		H. McCoy Kiss Tomorrow Goodbye in Four Novels (1983) 126: He’s left himself wide open, pulling a shakedown like this.
1956		‘Charles Raven’ Und. Nights 24: She was on the bogies’ short list and wide open for the future.
1971		(con. 1930s) D. Wells Night People 68: ‘Wide open spaces!’ That means a high-sitting woman. [Ibid.] 117: high-sitting Sitting carelessly, legs apart.

3. (US) of driving, very fast [the throttle is ‘wide open’].

2002

St Petersburg Times 26 July 🌐 Aaron attributes his success to his wide-open driving style, which combines impeccably timed passing with aggressive maneuvering through both left- and right-hand turns.

4. in fig. senses.