It hasn't changed meaning, that's the only thing that it ever meant.* Religious practices are a hugely relevant distinction for the history of the Roman Empire, the same way it is relevant to distinguish pre-Islamic and Islamic Arabia. Early Christianity and Islam radically transformed the lives of the people subjected to them.
Just because the technical use of a term is not familiar to lay people doesn't mean it is unclear or unhelpful. Here on HN, we all know what C-style strings are, even if an ordinary person might hear that and picture some kind of nautical rope.
* In English, at least. The Latin word paganus did change meaning (the original sense was 'rural'), but this occurred centuries before the emergence of English.
Just because the technical use of a term is not familiar to lay people doesn't mean it is unclear or unhelpful. Here on HN, we all know what C-style strings are, even if an ordinary person might hear that and picture some kind of nautical rope.
* In English, at least. The Latin word paganus did change meaning (the original sense was 'rural'), but this occurred centuries before the emergence of English.