Green’s Dictionary of Slang

belle-chose n.

[Fr. belle chose, a beautiful thing; coined by Geoffrey Chaucer (c.1345–1400)]

a lit. euph. for the vagina.

[UK]Chaucer Wife of Bath’s Prologue line 444: Is it for ye wolde have my queynte allone? [...] For if I wolde selle my bele chose, I coude walke as freshe as is a rose.
[UK]Farmer & Henley Sl. and Its Analogues.