Female abandons ostentatious thong (4)
I believe the answer is:
lash
'thong' is the definition.
(synonyms)
'female abandons ostentatious' is the wordplay.
'female' becomes 'f' (common abbreviation).
'abandons' suggests deleting specific letters.
'ostentatious' becomes 'flash' (I've seen this before).
'flash' with 'f' taken away is 'LASH'.
(Other definitions for lash that I've seen before include "Whip or scourge" , "Strike with a whip" , "over the eye" , "Birch" , "Sweep" .)