- -ist agent noun suffix, also used to indicate adherence to a certain doctrine or custom, from Fr. -iste and directly from L. -ista, from Gk. -istes, from agential suffix -tes. Variant -ister (e.g. CHORISTER (Cf. chorister), BARISTER (Cf. barister)) is from O.Fr. -istre, on false analogy of ministre. Variant -ista is from Spanish form, popularized in English 1970s by names of Latin-American revolutionary movements.
Etymology dictionary. 2014.