"Boo'd Up" singer Mai (4)
I believe the answer is:
ella
'boo'd up singer mai' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ella that I've seen before include "- - Fitzgerald (mus.)" , "- Wheeler Wilcox, US poet" , "Ms Fitzgerald" , "Miss" , ".... Fitzgerald, late great jazz diva" .)