[colechristensen]

Romans were polytheistic and didn't really have a name for their religion, nor did they think of it collectively as one thing separate from other religions, though very occasionally a set of practices might be referred to as what translates to "the Roman religion". Separate religions is really more of a monotheism thing. "Pagan" wasn't ever a self-identifying thing until well after the Christians took over and called them that for a long time.

"Foreign religions" weren't really much of a thing either, there were lots of gods and each village and city (and family really) would have their own versions of gods. Sometimes when you'd conquer a city you'd go to the most prominent temple and steal the statue or alter or whatever and bring it back to Rome with the vibe that you were stealing the god of the place you conquered.