In addition to its modern sense, in Middle English 'queynte' also = 'cunt'.
For, certeyn, olde dotard, by youre leve,
Ye shul have queynte right ynogh at eve.

Is it for ye wolde have my queynte allone?

Geoffrey Chaucer, The Wife of Bath's Prologue

As clerkes ben ful subtile and ful queynte;
And prively he caughte hire by the queynte
Geoffrey Chaucer, The Miller's Tale

The usage in Chaucer is clearly vulgar: the word occurs not in the poet's own voice but in the monologues of two of his most plain-speaking characters, the Miller and the Wife of Bath.