Kopplin rhymes with:
coplin, koplin, choplin, coplin, joplin, koplin, poplin, aplin, applin, caplin, champlin, choplin, coplin, eplin, esplin, joplin, kaplin, kemplin, koplin, pamplin, poplin, striplin, tamplin, taplin, templin
Kopplin sounds like:
kaplain, kaplan, kaplin, kappelman, kevlin, kopelman, koplan, koplin, koppelman