1790, "one who maintains the doctrine of sexes in plants;" see sexual in the original sense + -ist.
Entries linking to sexualist
sexual adj.
1650s, "distinctive of either sex, of or pertaining to the fact of being male or female," from Late Latin sexualis "relating to sex," from Latin sexus "a sex, state of being either male or female, gender" (see sex (n.)).
The meaning "pertaining to copulation or generation" is from 1766, on the notion of "done by means of the two sexes;" hence also "pertaining to erotic appetites and their gratification" and "peculiar to or affecting the organs of sex, venereal" (1799). The phrase sexual intercourse is attested by 1771 (see intercourse), sexual orientation by 1967, sexual harassment by 1975. Sexual revolution is attested by 1962. Sexual politics is from 1970. Related: Sexually.
-ist
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.