Mammoth Uncensored Word List:
31 - 18 letter words starting with su

subcategorizations subclassifications subconsciousnesses submicroscopically subminiaturization subrepresentations substitutabilities superadministrator superciliousnesses supercivilizations superconglomerates superconsciousness supereffectiveness superenergetically superintellectuals superintelligences superminicomputers supernaturalnesses superrighteousness supersagaciousness supersecretiveness supersensitisation supersensitiveness supersensitivities supersensitization supersentimentally supersophisticated superstrenuousness supersymmetrically supersynchronously supranationalities