Green’s Dictionary of Slang

phoenix nest n.

the vagina.

c.1618		Massinger & Field Fatal Dowry (1632) III i: He toil’d to climb vp to the Phoenix nest, And in his prints leaves your ascent more easie.
1648		R. Herrick ‘Love perfumes all Parts’ Hesperides 64: If I kisse Anthea’s brest, / There I smell the Phoenix nest [...] Hands, and thighs and legs, are all / Richly Aromaticall.
1655		J. Cotgrave ‘A Rapture’ Wits Interpreter (1671) 230: The Phoenix too must build his nest.
1707		J. Shirley Triumph of Wit 131: A good wife to find, is a Phoenix’s Nest, / With Spices, and plenty of Odours still built, / But beware you mistake not in chusing a Jilt.
1812		W. Tennant Anster Fair I xxiii 13: Ne’er smelt a Phoenix-nest so sweet, I wot, / As smelt the luscious fumes of Maggie’s mustard-pot.
1842		‘The Swell Coves Alphabet’ Nobby Songster 29: P, stands for patent pills, Phoenix Alley and the P---.