pastoralist (n.)

early 15c., "of or pertaining to shepherds or the life of a shepherd," from Old French pastoral (13c.) and directly from Latin pastoralis "of herdsmen, of shepherds," from pastor "shepherd" (see pastor (n.)). Meaning "of or pertaining to a Christian pastor or his office" is from 1520s. The noun sense of "poem treating of or descriptive of country life generally," usually in an idealized form and emphasizing its purity and happiness, in which the characters are shepherds or shepherdesses, is from 1580s.

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.