Here's what rhymes with columnatum.
                        
                        
                    
                                datum  stratum  substratum  Words that almost rhyme with columnatum
madam  madame  satin  fatten  latin  batten  madden  happen  imagine  hadn  cabin  haben  flatten  macadam  platen  sadden  gladden  tarmacadam  maxim  chasm  fathom  phantom  magnum  tantum  sachem  bantam  handsome  random  platinum  amalgam  ransom  spasm  tandem  plasm  sanctum  tantrum  hansom  phantasm  talcum  pablum  memorandum  nonrandom  transom  gladsome  sphagnum  neoplasm  iconoclasm  enthusiasm  cytoplasm  protoplasm