“Pax” is Latin, right? Is it also the French for “peace”?
paix is french for peace according to altavista babelfish.
WE SURRENDER!!!
Sorry… 
Now cut that out, Ants!
Thanks, Lobsang. So is the street spelled "rue de la Paix"?
Yes, it is.
Note that the “x” is silent. A rough approximation of how it’s pronounced would be: peh. More or less.
or ‘pay’
But if you say it as “pay”, you get that trailing “y” sound that’s not supposed to be there and the intonation is lower than it should be. How about: say the word “pelt” and drop the last two letters. The vowel sound should be short and even.
I actually thought the trailing ‘y’ sound was necesary. If not then ‘peh’ is the ideal pronunciation.
“Paix” is peace, and both those pronunciations sound right to me (at least with my accent, and most others I can imagine)
If you stick a ‘y’ on the end, it sounds more like “pays”, or country.
“Mon pays n’est pas à la paix”… Sorry.
Francophone checking in here. “peh” is a more accurate pronunciation than “pay”. I’ve never heard “paix” pronounced as “pay”, and as Nanoda so accurately pointed out, it would likely be confused with pays, the word for country (which, incidentally, is pronounced, “payee”).
Just my 2c.
Max.
I’d say ‘paih.’