Ketter rhymes with:
better, bettor, debtor, detter, etter, fetter, fretter, geter, getter, jetter, letter, metter, mettur, netter, petr, petre, petter, pipetter, retter, schetter, setter, shetter, stetter, sweater, tretter, tschetter, vetere, vetter, wetter, yetter
Ketter sounds like:
kadar, kader, kaster, kater, keator, kedar, keeter, keister, keiter, kester, ketterer, ketura, kidder, kiesewetter, kiester, kister, koester, koether, koetter, kohtaro, kohtoro, kooistra, koster, kotara, kothari, kotter, kuder, kuester, kuether, kuster, kustra, kuter, kutter