Mammoth Uncensored Word List:
23 - 16 letter words starting with mu

muddleheadedness multibillionaire multicellularity multicrystalline multiculturalism multidimensional multidimentional multidirectional multidisciplines multifactorially multifariousness multihandicapped multilateralisms multilateralists multilingualisms multimillionaire multiplicatively multiprocessings multiprogramming municipalisation municipalization musculocutaneous musculoskeletals