User blog comment:CNBA3/Chapter 439: Alvarez Empire Prediction/@comment-49.148.218.170-20150603070812/@comment-7418318-20150603191912

According to translation sites on the net, caelum is latin for a surprising variety of words including among others "sky", "chissel" and "climate" oO

So there's plenty of room for it to have a meaning completely independant of the Celestial Spirit Caelum.

Since Caelum is only a silver spirit and not even a unique one, I doubt any country would be named after it.