Source : Webster's Revised Unabridged Dictionary (1913)

Ism \Ism\, n. [See {ism}, above.]
   A doctrine or theory; especially, a wild or visionary theory.
   --E. Everett.

         The world grew light-headed, and forth came a spawn of
         isms which no man can number.            --S. G.
                                                  Goodrich.

Source : WordNet®

ism
     n : a belief (or system of beliefs) accepted as authoritative by
         some group or school [syn: {doctrine}, {philosophy}, {philosophical
         system}, {school of thought}]