Толковый словарь английского языка Oxford English Reference - ist

suffix forming personal nouns (and in some senses related adjectives) denoting: 1 an adherent of a system etc. in - ism: see -ISM 2 (Marxist; fatalist). 2 a a member of a profession (pathologist). b a person concerned with something (tobacconist). 3 a person who uses a thing (violinist; balloonist; motorist). 4 a person who does something expressed by a verb in -ize (plagiarist). 5 a person who subscribes to a prejudice or practises discrimination (racist; sexist). Etymology: OF -iste, L -ista f. Gk -istes