Anoint a Byzantine lady (7)
I believe the answer is:
antonia
'lady' is the definition.
(I've seen this before)
'anoint a byzantine' is the wordplay.
'byzantine' indicates an anagram (byzantine means complex or confusing).
'anoint'+'a'='anointa'
'anointa' with letters rearranged gives 'ANTONIA'.
(Other definitions for antonia that I've seen before include "female" , "lady" , "Girl's name" , "woman" .)