late 14c., ydolatrer "idol-worshipper," from Old French idolatre, contracted from Late Latin idololatres, from Ecclesiastical Greek eidololatres "idol-worshipper," related to eidolatria (see idolatry).
word-forming element making adjectives from nouns, meaning "having, full of, having to do with, doing, inclined to," from Old French -ous, -eux, from Latin -osus (compare -ose (1)). In chemistry, "having a lower valence than forms expressed in -ic."
<a href="https://www.etymonline.com/word/idolatrous">Etymology of idolatrous by etymonline</a>
Harper, D. (n.d.). Etymology of idolatrous. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/idolatrous