Definition of "parliamentarian"

Our participation in the parliament does not indicate a support, but rather an undermining of the parliamentarian system.

1946, Office of United States Chief Counsel For Prosecution of Axis Criminality, Nazi Conspiracy and Aggression, Washington, Volume 1, citing Wilhelm Frick

[...] Deputies were sent with Commissions into all the Counties; and the Parliamentarian Rebels by force and their own authority, invade the Militia, which they could not obtain from the King by petitioning.

1685, George Bate, Elenchus Motuum Nuperorum in Anglia, or, A Short Historical Account of the Rise and Progress of the Late Troubles in England‎, London, page 41

But while he continued there, he shew’d himself a Dunce, a Tale-bearer to the Parliamentarian Visitors that then acted in the University, and a factious person.

1692, Anthony Wood, Athenæ Oxonienses‎, volume 2, London: Thomas Bennet, page 291

The Scotch and parliamentarian army had joined, and were beſieging York; when prince Rupert, joined by the marquis of Newcaſtle, determined to raiſe the ſiege.

1771, [Oliver] Goldsmith, “Charles I. (Continued.)”, in The History of England, from the Earliest Times to the Death of George II. […], volume III, London: […] T[homas] Davies, […]; [T.] Becket and [P. A.] De Hondt; and T[homas] Cadell, […], page 271

There were large regions which were very decidedly royalist, others almost as distinctly parliamentarian [...]

1895, Hereford Brooke George, chapter 9, in Battles of English History,‎, London: Methuen, page 128