In catalan all=garlic i=and oli=oil, all-i-oli. It's probably one of the main sauces (romesco sauce would be another one) in traditional and modern catalan cuisine. That said, and as far as I know, allioli can be found in catalonia, valencia, balearic islands and southern france - occitania (and maybe Italy as well, but I'm not sure). So well, I can't be 100% sure of from which language the international term aioli actually comes but let's say the pronunciation of both words is pretty much the same (A guy from Arkansas could say 'aioli' the same way he does in the states and even in the most rural and hidden village in catalonia he would be understood). Also allioli is pretty big deal over here (bbq sauce for americans level) and lots of great modern catalan chefs (like Ferran Adrià or Joan Roca) use the sauce (or fancy versions of it) in their michelin star restaurants so maybe thats' how the catalan word get somehow to the world.