Flexion rhymes with:
inflection, reflection, collection, election, inflection, predilection, preelection, recollection, reelection, reflection, selection
Flexion sounds like:
falcigno, falcon, falcone, falconi, falsone, falzon, falzone, faulcon, feliciano, felleisen, filson, flagman, flagmen, flashgun, flaxman, fleischman, fleischmann, fleishman, fleshman, folkman, folsom, folson, fulgham, fulghum, fulsome