Melydia sounds like a disease.
I agree on this one. Also, having straightforward easy to spell names to be important. If I heard melydia I'd ask "and how do you spell that?". I just sat back and thought of all the other big name internet sites, and I don't feel this would be the case for any of them. Weird historical stuff doesn't really do much except when people write about the service they can say "The name ..... means .... in greek'. Outside of that I don't see any value in using obscure foreign words. If the root word is similarly suggestive across languages it would be a positive trait.
Also it sounds like a disease... To me it isn't suggestive of melody or melodic.
I like Joeyd's idea of an acronym sounding name, where what it stands for could possibly vary across languages.
At some point we need to get the top 5-10 options together and put them in a poll ? Not sure the userbase is large enough to give a really good result though. It'd be such a small poll anyone with sock puppets could dominate it.
I'm still a a fan of Canary. Simple and suggestive. Lends itself to all manner of cute logos. When you create new words, the person has to remember the new word before they can associate the new word as the name of the service. If you choose a name/word that people are familar with, they skip the first step. This is why I believe I have a harder time remembering foreign names.