in the economics sense of "one who favors protection of native industry or some branch of it from foreign competition by means of tariffs, etc.," 1841, from French protectionniste (in political economy sense, protection in English is attested from 1789). As an adjective by 1843.
word-forming element making nouns implying a practice, system, doctrine, etc., from French -isme or directly from Latin -isma, -ismus (source also of Italian, Spanish -ismo, Dutch, German -ismus), from Greek -ismos, noun ending signifying the practice or teaching of a thing, from the stem of verbs in -izein, a verb-forming element denoting the doing of the noun or adjective to which it is attached. For distinction of use, see -ity. The related Greek suffix -isma(t)- affects some forms.
<a href="https://www.etymonline.com/word/protectionism">Etymology of protectionism by etymonline</a>
Harper, D. (n.d.). Etymology of protectionism. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/protectionism