Mammoth Uncensored Word List:
107 words ending with m, 15 letters long

angiocardiogram annihilationism anthropopathism anticlericalism anticolonialism antimaterialism antirationalism antiromanticism archaebacterium archeomagnetism assimilationism autodidacticism bacchanalianism blennorrhagicum bluestockingism brachycephalism brachydactylism confessionalism conservationism constructionism conventionalism conversationism corynebacterium cosmopolitanism cryptosporidium departmentalism dermatographism diaheliotropism diaphototropism doctrinarianism ecclesiasticism enantiomorphism enterobacterium entrepreneurism episcopalianism equalitarianism experientialism experimentalism ferromolybdenum futilitarianism governmentalism heliocentricism hereditarianism hermaphroditism humanitarianism hyperadrenalism hypercatabolism hyperinsulinism hypermetabolism hyperparasitism hyperthyroidism hypopituitarism infundibuliform instrumentalism insurrectionism intellectualism interambulacrum interventionism intransigentism macrometabolism macrosporangium majoritarianism mechanomorphism melodramaticism metropolitanism microsporangium multilateralism multilingualism neoconservatism neuroepithelium nonessentialism nothingarianism oneirocriticism opisthognathism organomagnesium orthochromatism palaeomagnetism parliamentarism phonocardiogram photofluorogram photojournalism poikilothermism polysyllabicism preferentialism preformationism presbyterianism presentationism professionalism resurrectionism scaphocephalism scolopendriform semicolonialism solvatochromism stereoisomerism sublapsarianism supernaturalism superorganicism superparasitism superpatriotism supersensualism tetrasporangium therianthropism thermoperiodism thromboembolism totalitarianism ubiquitarianism ultraliberalism