Green’s Dictionary of Slang

1. the vagina [rhy. sl. = fanny n.¹ (1)].

1999		Roger’s Profanisaurus in Viz 98 Oct. 18: Jacky Danny rhym. slang James Hunt (qv).
2002		D. Shaw ‘Dead Beard’ at www.asstr.org 🌐 My better half has Dionne kneeling down on her hands and knees with her jack and danny sticking up on offer.
2003		B. Dark Dirty Cockney Rhy. Sl.

2. nonsense, time-wasting, prevarication [rhy. sl. = fanny n.² ].

2000

J.J. Connolly Layer Cake 16: A straight question needs a straight answer, no Jack and danny, are you willing to come on board as a partner?