What doess Sora name mean in Kingdom Hearts?

Most of the names in kingdom hearts are Japanese Words

Sora - Sky

Riku - Earth

Kairi - agony of separation (kinda poetic, huh?)

and all of the nobody's names are just their original self's name plus an x and rearrange (axel's name was lea, saix's name was isa, xemnas' name was ansem)

and most of the names of their original self's have no meaning in Japanese (which leads to the conclusion that they don't mean ANYTHING at all, because Square-Enix is a Japanese company)