DuckCorp Dico

Found one definition

1.                 From Japanese-English FreeDict Dictionary ver. 0.1:
                   
   
   
                   
                     
   冪 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 羃 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, 巾 /(en)tʃˈaɪniːz(ja)lˈe̞tə/, べき /bˈe̞ki/
   (noun (common) (futsuumeishi))
    [mathematics] exponent, power