Copelin rhymes with:
zeppelin, asselin, candilin, ethelyn, formylin, gamelin, gosselin, hagelin, iselin, jackelyn, jacquelyn, joscelyn, josselyn, lemelin, llewelyn, madelyn, marilin, marylin, myelin, rosselin, zeppelin
Copelin sounds like:
cableone, caplan, caplin, cephalon, chaplain, chaplan, chaplin, choplin, cipollone, civilian, cofflin, copelan, coplan, coplen, coplin, coppolino, couvillion, couvillon