The Collaborative International Dictionary of English v.0.48:

Methodism \Meth"o*dism\, n. (Eccl.)
   The system of doctrines, polity, and worship, of the sect
   called Methodists. --Bp. Warburton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Methodism
    n 1: the religious beliefs and practices of Methodists
         characterized by concern with social welfare and public
         morals