Quin | Webster's Dictionary of the English Language

quin
quīn, conj. [abl. quī and ne]. I As an interrog. particle , why not? wherefore not? (only in ex...

A New Latin Dictionary by Charlton T. Lewis Ph.D. and Charles Short, LL. D.
quin
quīn conj. I 2 qui+-ne. I I. In a principal clause, interrog., why not? wherefor...

An Elementary Latin Dictionary