Green’s Dictionary of Slang

1. (also pross) a prostitute; prostitution [abbr.].

1884		‘Experiences of a Cunt Philosopher’ in Randiana 77: She has excited me to such an extent that [...] I shall really have to go into the village and seek out an ordinary ‘pros’.
1895		C. Crowe Aus. Sl. Dict. 61: Pros, contraction for prostitute.
1905		Sessions Papers 8 Feb. 556: She is only a pros.; you know her.
1914		E. Wittmann ‘Clipped Words’ in DN IV:ii 123: pross, also prossy. A prostitute.
1935		G. Ingram Cockney Cavalcade 237: ‘I can see you got in with some “prosses”.’ ‘Oy, not so much of it,’ interrupted one of the girls, ‘with your “prosses”!’.
1941		Baker Popular Dict. Aus. Sl. 57: Pros [...] a prostitute.
1943		J. Phelan Letters from the Big House 79: With a pross, it wouldn’t arise.
1956		J. Stearn Sisters of the Night 82: If he finds out I’m a pros, that would end it.
1961		T.I. Rubin In the Life 6: Is that what you want to know, about my sex life, the sex life of a pross?
a.1964		‘Honky-Tonk Bud’ in D. Wepman et al. Life (1976) 57: Douche-Mouth Eddie with a pros called Betty / Was calmly digging the scene.
1972		Hall & Adelman Gentleman of Leisure 39: If you get a weak pross, she’s going to be handled by the johns. They’ll use her.
1981		G. Young Slow Boats to China (1983) 176: ‘The prosses have all gone.’ ‘Prosses?’ ‘Prostitutes – girls and women, mostly from India. The Dubai government sent them off home.’.
1989		J. Morton Lowspeak.
2008		R. Price Lush Life 208: I always knew about that guy and his thing for pross .

2. attrib. use of sense 1, pertaining to prostitution.

1968		N. Heard Howard Street 174: ‘She’. Pros charge, huh?
1981		A.K. Shulman On the Stroll 147: Either an easy trick or a pros cop, thought Robin.

3. (N.Z. prison) a canbdidate for gang membership, a prospect n. (2)

1992		A. Duff One Night Out Stealing 136: Tellin Nig he had a dude arranged to rumble with. It was outta him and this other pros from town sumwhere.
2001		D. Looser Boobslang [U. Canterbury D.Phil. thesis] 146/2: pros (also proz) n. = prospect.

4. see pross n.¹ (2)