Female expert's look (4)
I believe the answer is:
face
'look' is the definition.
(I know that look can be written as face)
'female expert's' is the wordplay.
'female' becomes 'f' (common abbreviation).
'expert' becomes 'ace' (ace can informally mean very good).
'f'+'ace'='FACE'
(Other definitions for face that I've seen before include "'Cheeks, mouth, eyes etc (4)'" , "Deal with" , "cheek" , "Confront - mug (slang)" , "Come up against" .)