supremist (n.)

1520s, from French suprême (15c.) and directly from Latin supremus "highest," superlative of superus "situated above," from super "above" (from PIE root *uper "over"). Supreme Being "God" first attested 1690s; Supreme Court is from 1689.

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.

by 1948, originally with reference to racial beliefs and in most cases with white, from supremacy + -ist. Compare supremist. Related: Supremacism.