Fling is overlooked by female, I suspect (5)
I believe the answer is:
fishy
'suspect' is the definition.
(synonyms)
'fling is overlooked by female i' is the wordplay.
'fling' becomes 'shy' (I've seen this before).
'is overlooked by' means one lot of letters go next to another (in a down clue, some letters go above others).
'female' becomes 'f' (common abbreviation).
'f'+'i'='fi'
'shy' put after 'fi' is 'FISHY'.
(Other definitions for fishy that I've seen before include "Dubious - piscatorial" , "Suspicious (as trout?)" , "Ray is so" , "Suspect" , "Suspicious, shady" .)