Queen of the fairies (7)
I believe the answer is:
titania
'queen of the fairies' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for titania that I've seen before include "Bottom fan" , "Queen of the fairies - Uranus satellite" , "asinine lover" , "in the D [DREAM] ..." , "Oberon's queen (MND)" .)