I was translating a song lyric and saw that the expression "c'est plus pareil" translates to "it's not the same". This translation doesn't make sense to me, as there are no negation words like "ne" or "pas". For me, the right expression should be "ce n'est pas plus pareil". The expression "c'est plus" indicates negation? I couldn't find that expression by searching in dictionaries.
The first part of split negatives (ne) tend to disappear in French, so c'est plus pareil is simply the spoken French version of ce n'est plus pareil ("it's no longer the same").
Here plus is enough to understand it is a negation, especially when hearing the sentence because its final S is not pronounced.
There is then another c'est plus pareil where the same S is heard (/plys/ vs /ply/). This form stays the same whatever the language register and means "It's more the same".
Note also that ce n'est pas plus pareil is unlikely to be heard but would be understood (with /ply/) as a double negative "it's not no longer the same".