Girl I complain about (5)
I believe the answer is:
naomi
'girl' is the definition.
'i complain about' is the wordplay.
'complain' becomes 'moan' (I've seen this before).
'about' is a reversal indicator.
'i'+'moan'='imoan'
'imoan' reversed gives 'NAOMI'.
(Other definitions for naomi that I've seen before include "Girl" , "woman's name" , "OT female" , "mother- in-law" , "Mother-in-law of Ruth (Bible)" .)