Usually it's fairly easy to know the spelling of words in Italian, given the very close relation between that and pronunciation.
But that's not always true. The word musulmano in Italian (which means Muslim), has one S, but it's pronounced like it had two. There is actually an alternative spelling, mussulmano, but I've personally never seen it used so much. Besides, it doesn't explain that much about what I'm wondering.
The dictionary states that the etymology is from the Arabian-Persian muslimān. I'm sure we have other loanwords from the Arabic language, and as far as I can remember, none of them stands out like this one.
Italian has a rule about the S in inter-vowel position, but my example is pronounced like an actual SS. See for example:
- casa - cassa;
- dosi - dossi;
- leso - lesso.
The first examples, are not pronounced with a voiced S, but they are still distinguishable from the second ones, not only because in actual language not everyone pronounces it voiceless, but also because it's less stressed if compared to the second examples.
So my questions are, what is this phenomenon called (if it is)? And why did it happened, apparently, to this word only? Or are there other examples?
Probably the reason is that earlier it was written as "mussulmano", then that changed and pronunciation stayed the same, but I'd like to know if this guess is confirmed or not.