what does azumanga daioh literally means?

"Azumanga" is a combination of "Azuma", which is the author's name, and "manga", the Japanese term for comics. "Daioh" comes from the magazine in which Azumanga daioh was originally published, Dengeki Daioh. In the anime, "Daioh" is mentioned during the next episode previews, in context meaning "great king". As you can see, its title doesn't really have its significance with the story. I wonder why they chose it as the title.