roy·al·ist / ˈroiəlist/ • n. a person who supports the principle of monarchy or a particular monarchy. ∎ a supporter of the king against Parliament in the English Civil War. ∎ a supporter of the British during the American Revolution; a Tory.• adj. giving support to the monarchy: the paper claims to be royalist. ∎ (in the English Civil War) supporting the king against Parliament: the royalist army.DERIVATIVES: roy·al·ism / -ˌizəm/ n.