1914, "of a monetary character or having a monetary basis," from monetary + -ist. As a noun, "one who advocates tight control of the money supply to remedy inflation," by 1963. Related Monetarism (1963).
1802, "pertaining to coinage or currency;" 1860, "pertaining to money;" from Late Latin monetarius "pertaining to money," originally "of a mint," from Latin moneta "mint; coinage" (see money (n.)). Related: Monetarily.
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.
<a href="https://www.etymonline.com/word/monetarist">Etymology of monetarist by etymonline</a>
Harper, D. (n.d.). Etymology of monetarist. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/monetarist