monarchist n.

mid-14c., monarchie, "a kingdom, territory ruled by a monarch;" late 14c., "rule by one person with supreme power;" from Old French monarchie "sovereignty, absolute power" (13c.), from Late Latin monarchia, from Greek monarkhia "absolute rule," literally "ruling of one," from monos "alone" (from PIE root *men- (4) "small, isolated") + arkhein "to rule" (see archon). Meaning "form of government in which supreme power is in the hands of a monarch" is from early 15c.

word-forming element meaning "one who does or makes," also used to indicate adherence to a certain doctrine or custom, from French -iste and directly from Latin -ista (source also of Spanish, Portuguese, Italian -ista), from Greek agent-noun ending -istes, which is from -is-, ending of the stem of verbs in -izein, + agential suffix -tes.

Variant -ister (as in chorister, barrister) is from Old French -istre, on false analogy of ministre. Variant -ista is from Spanish, popularized in American English 1970s by names of Latin-American revolutionary movements.