Parliamentarian can refer to a member or supporter of a Parliament, as in: Member of Parliament Roundheads, supporters of the parliamentary cause in the English Civil War Parliamentarian can also refer to an expert adviser on parliamentary procedure, as in: Parliamentarian (consultant) - An officer or outside consultant designated by an organization to serve as an expert in parliamentary procedure Parliamentarian of the United States House of Representatives Parliamentarian of the United S… (More on Parliamentarian)