Webster's Revised Unabridged Dictionary · 1913

Parliamentarian

Parliamentarian , adjective

Of or pertaining to Parliament. — Wood

Parliamentarian , noun

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.