Green’s Dictionary of Slang

1. a prostitute.

1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1890–1904		Farmer & Henley Sl. and Its Analogues.

2. a woman who regularly attends military balls.

1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1890–1904		Farmer & Henley Sl. and Its Analogues.
1924		Lawrence & Skinner Boy in the Bush 255: It was the twentieth dance. Jack had been introduced to a sporting girl in her late twenties [...] Tom called her a ‘barrack hack’.
1924		F.B. Young Woodsmoke 265: ‘I have never met a woman to touch her,’ he thought, ‘and here have I been treating her as if she were a barrack hack.’.