Friederich rhymes with:
friederike, friederike, diederich, friederike, broderick, dederick, diederich, friederike, honderich, alaric, berberich, broderick, butterick, choleric, cyanuric, dederick, diederich, dieterich, emerich, emerick, emmerich, friederike, garverick, giegerich, gingerich, gregorich, helmerich, hemmerich, honderich, kanarek, kasparek, kasperek, kauzlarich, klapperich, leverich, limerick, maverick, millerick, minarik, pekarek, phosphoric, puskarich, rhetoric, safarik
Friederich sounds like:
fortier's, fortress, fortresses, forwarders, frederic, frederica, frederick, frederick's, fredericka, fredericks, frederico, frederika, fredric, fredrich, fredrick, fredricks, fridrich, friederike, friedrich, friedrichs, friedrick, furthers