The Collaborative International Dictionary of English v.0.48:

Presbyterian \Pres`by*te"ri*an\, n. [Cf. F. presbyt['e]rien.]
   One who maintains the validity of ordination and government
   by presbyters; a member of the Presbyterian church.
   [1913 Webster]

   Reformed Presbyterians. See Cameronian.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Presbyterian \Pres`by*te"ri*an\, a. [Cf. F. presbyt['e]rien.]
   Of or pertaining to a presbyter, or to ecclesiastical
   government by presbyters; relating to those who uphold church
   government by presbyters; also, to the doctrine, discipline,
   and worship of a communion so governed.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Presbyterian
    n 1: a follower of Calvinism as taught in the Presbyterian
         Church

The Devil's Dictionary (1881-1906):

PRESBYTERIAN, n.  One who holds the conviction that the government
authorities of the Church should be called presbyters.