Grethel rhymes with:
bethel, bethell, ethel, ethyl, methyl, pethel, pethtel, barthel, benthall, bethel, bethell, bothell, brothel, cathell, ethel, ethyl, freudenthal, laubenthal, lethal, lilienthal, loewenthal, lowenthal, methyl, nonlethal, odenthal, pethel, pethtel, raithel, rathel, ruppenthal, southall, walthall
Grethel sounds like:
gardella, gartley, girdle, girdley, gordillo, gradel, gradual, gradually, grathwohl, greatly, gredel, greedily, gretal, gretel, gridley, guardedly, guardiola