What you might call an expensive woman (4)
I believe the answer is:
dear
'what' is the definition.
Both the answer and definition are adverbs.
Maybe you can see an association between them that I don't see?
'you might call an expensive woman' is the wordplay.
I cannot really understand how this works, but
'an' could be 'a' and 'a' is present in the answer.
'woman' could be 'de' and 'de' is present in the answer.
A single letter 'r' remains which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for dear that I've seen before include "Treasured" , "Highly priced" , "polite form of address" , "address for partner" , "Needing plenty of bread" .)