Board Thread:Online Discussion/@comment-5149194-20130621212349/@comment-8209010-20130727005345

Aldmer was the name of the original elves. Then, when new kinds started to appear, they needed new names for each. So, "Aldmer" probably means "Old elves" in Aldmeris, like Dunmer means "Dark elves". So when that happened, "Old elves" didn't really fit, since the High Elves thought themselves as better than the other elvenkind and named themselves that. So, by changing to "High Elves" the name in Aldmeris changed to "Altmer", which means "High elves"