Source : Webster's Revised Unabridged Dictionary (1913)

Parliamentarian \Par`lia*men*ta"ri*an\, a.
   Of or pertaining to Parliament. --Wood.

Parliamentarian \Par`lia*men*ta"ri*an\, n.
   1. (Eng. Hist.) One who adhered to the Parliament, in
      opposition to King Charles I. --Walpole.

   2. One versed in the rules and usages of Parliament or
      similar deliberative assemblies; as, an accomplished
      parliamentarian.

Source : WordNet®

Parliamentarian
     n 1: an elected member of the British Parliament: a member of the
          House of Commons [syn: {Member of Parliament}]
     2: an expert in parliamentary rules and procedures