Green’s Dictionary of Slang

(orig. tramp) a woman, esp. one seen as sexually appealing and/or of loose character.

1886		W. Newton Secrets of Tramp Life Revealed 8: Buor ... A Woman.
1891		Birmingham Dly Post 31 Mar. 3/5: It may be also that ‘beaua,’ pronounced ‘bewa,' meaning a woman or wife,'haz some relation to the French ‘beau’.
1891		F.W. Carew Autobiog. of a Gipsey 416: My missus – as fly a bewer, she were, as ever chucked a stall, a reg’lar tip-top tamtart.
1938		G. Greene Brighton Rock (1943) 24: She don’t matter [...] She’s just a buer.
2005		B. Hare Urban Grimshaw 3: There’s an ugly fucking buah, called Trudi, the slag, / and we all hate her because she’s a bag.
2015		L. McInerney Glorious Heresies 254: [S]he’d been his first, he’d pulled out and he didn’t really like the beour in the first place.