Here's what rhymes with diphtherias.
cafeterias Words that almost rhyme with diphtherias
serious mysterious imperious delirious bilious deleterious supercilious punctilious paterfamilias patresfamilias cereals serials zinnias periods finials simians arrhythmias insignias deliriums forsythias materials amphibians meridians presidiums praesidiums criterions condominiums antibacterials