Fretter rhymes with:
retter, tretter, better, bettor, debtor, detter, etter, fetter, geter, getter, jetter, ketter, letter, metter, mettur, netter, petr, petre, petter, pipetter, retter, schetter, setter, shetter, stetter, sweater, tretter, tschetter, vetere, vetter, wetter, yetter
Fretter sounds like:
fairweather, farther, ferderer, ferriter, fortier, forwarder, frater, frieder, fritter, froder, further