Female, poorly, breaking down (7)
I believe the answer is:
failing
'breaking down' is the definition.
('fail' can be a synonym of 'break down')
'female poorly' is the wordplay.
'female' becomes 'f' (common abbreviation).
'poorly' becomes 'ailing' (synonyms).
'f'+'ailing'='FAILING'
(Other definitions for failing that I've seen before include "Defect" , "conking out" , "Weak point" , "Character weakness" , "becoming frail" .)