Queen once has European hat back to front in part of UK (9)
I believe the answer is:
nefertiti
'queen' is the definition.
(I've seen this before)
'once has european hat back to front in part of uk' is the wordplay.
I cannot really see how this works, but
'european' could be 'e' (abbreviation e.g. EU) and 'e' is found in the answer.
'part' could be 'tit' (tit is a kind of part) and 'tit' is located in the answer.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for nefertiti that I've seen before include "African Queen" , "Oddly, the Egyptian queen is an entire fit" , "Queen on the Nile" , "old queen" , "Name of queen" .)