Here's what rhymes with cydonium.
                        
                        
                    
                                ammonium  zirconium  polonium  plutonium  meconium  harmonium  pandemonium  Words that almost rhyme with cydonium
chromium  draconian  amazonian  podium  sodium  symposium  rhodium  niobium  holmium  petroleum  linoleum  opprobrium  europium  dysprosium  colloquium