Source : Webster's Revised Unabridged Dictionary (1913)

Presbyterianism \Pres`by*te"ri*an*ism\, n. [Cf. F.
   presbyt['e]rianisme.]
   That form of church government which invests presbyters with
   all spiritual power, and admits no prelates over them; also,
   the faith and polity of the Presbyterian churches, taken
   collectively.

Source : WordNet®

Presbyterianism
     n : the doctrines and practices of the Presbyterian Church:
         based in Calvinism