Although the idea of idolatry has been present for a long time, I believe St. Paul is the first to use the term εἰδωλολατρία, e.g. Gal 5:20. (Corrections welcome!)
Two surprises come when we look at the Vulgate:
- εἰδωλολατρία is translated as "idolorum servitus" (Gal 5:20) or "idolorum cultura" (1 Cor 10:14)
- But: "idolatria" is used at least twice, to translate the Greek "κατείδωλον" (Acts 17:16) and "θεραφιν" (1 Sam 15:23, LXX) (which, I found out after some digging, is just a transliteration of Hebrew וּתְרָפִ֖ים (uterafim) = "household idol").
Although there are a lot of good questions that this cursory look bring up (many of which would probably find a better home at Biblical Hermeneutics), I will only ask one: Why was εἰδωλολατρία transcribed as idolatria rather than idololatria?