Green’s Dictionary of Slang

growler n.5

[growl and grunt n.]

1. the vagina.

[Ire]G. Coughlan Everyday Eng. and Sl. 🌐 Growler (n): female genitalia (hairy growler).
[NZ]McGill Reed Dict. of N.Z. Sl. 89: go for the growler Approach or engage a woman’s genitals. ANZ. [Ibid.] 93: growler Vagina. Recent local extension of rhyming slang identifying ‘cunt’ as ‘growl and grunt’. ANZ.
Twitter 13 Nov. 🌐 Britain's biggest-circulation newspaper has followed up its front-page coverage of Angela Rayner’s ‘growler’ with front-page coverage of Angela Rayner’s boobs.

2. in ext. use, an unattractive woman.

[UK]J.J. Connolly Layer Cake 253: I need blue ocean, seafood and fit birds, not growlers, shooters and grim-boat Londoners.
[UK]J.J. Connolly Viva La Madness 296: The O’Malleys pull every hound and growler for miles into their orbit.