Mammoth Uncensored Word List:
200 words ending with um, 9 letters long

achaenium aluminium americium anoestrum anthodium anthurium antiserum arbitrium arboretum asphaltum asplenium athenaeum avisandum avizandum bacterium barathrum berkelium beryllium botulinum bronchium bubblegum calcaneum caldarium calvarium capitulum carbonium castellum castoreum cerastium claustrum clitellum coccidium coenobium colchicum collegium collodium colluvium collyrium colosseum colostrum columbium combretum contagium continuum conundrum cormidium credendum cribellum criterium ctenidium cubiculum cymbidium decennium deliquium dentalium desmodium deuterium diachylum diacodium diatretum diazonium dichasium doronicum drepanium ectropium effluvium elaterium emplectum encolpium endosteum entropium epicedium epilobium epimysium equisetum euphonium excambium excerptum fastigium flabellum flagellum flerovium gastraeum gelsemium germanium glucinium gymnasium gynaeceum gynaecium gynoecium harmonium helvetium herbarium hieracium hordeolum hospitium hydronium hypericum hypogaeum impluvium indecorum lanthanum magnalium magnesium manubrium marsupium martyrium mausoleum mazaedium menstruum molluscum nelumbium neodymium neptunium nymphaeum operculum opusculum palladium paramylum pastorium perinaeum petroleum plutonium pollinium polygonum pomoerium potassium practicum prescutum presidium prooemium propodeum prytaneum pterygium purdonium pycnidium pyrethrum quaesitum quercetum reddendum reptilium responsum reticulum rhipidium rhizobium rostellum ruthenium saccharum sacrarium sagapenum salicetum sargassum sarmentum scutellum sensillum sensorium separatum septarium spirillum sporidium stomodeum strontium submentum subphylum sugarplum sulfonium sympodium symposium synangium syncytium synedrium taraxacum tegmentum tellurium tenaculum tentorium terrarium tormentum trapezium triennium trifolium triforium tripudium trisodium ultimatum unguentum ununtrium unununium uredinium uropygium vaccinium verbascum vestigium virginium viticetum vulsellum ytterbium zirconium zoocytium zygantrum