Fae
Elphaba had never been happy with her nicknames. Father called her Fabala, which she didn't understand the logic of as it was no shorter than her given name, but the occurrences were so rare it hardly mattered.
Glinda had happily dubbed her Elphie. Though she felt it didn't fit her at all, because it came from her first true friend she accepted it.
Fae, however, she could find no fault with (as long as it came from the right person, of course). Short and to the point, just a slight variation of the normal, not too perky, Fae she liked.