We unfortunately don't know for certain where the name Keizaal comes from or if it has any deeper meaning. Quick note that the word keiz is a fanmade word, so can't really be part of this dicussion.

"Kei" only appears in one other word, morokei 'glorious', as a suffix to moro 'glory', so that doesn't help much here. There is one other word that ends in "-zaal," unahzaal meaning "unending, ceaseless, eternal." If un-/unah- can be considered a negative (as in unslaad also meaning "unending, ceaseless, eternal"), then zaal on its own may mean something close to "end," "edge," or "rim."

This is all just speculation—you have to do some mental gymnastics to ignore the ah in unahzaal to make this work.