Here's what rhymes with knowswhen.
when wen wenn then men ten den pen hen ben ken sen yen fn pn chen denn fen jen ren wren again againe glen amen cayenne lawmen oilmen penmen anchormen pitchmen weathermen conmen businessmen middlemen comedienne handymen minutemen councilmen patrolmen signalmen tragedienne equestrienne Words that almost rhyme with knowswhen
them stem gem hem femme heme mem rem feng sheng hmm pm morpheme eadem condemn ppm rpm diadem blaspheme cairn moderne demesne fluorescein relearn ramequin