Genuine gold female found in loft, not the first (9)
I believe the answer is:
authentic
'genuine' is the definition.
(similar in meaning)
'gold female found in loft not the first' is the wordplay.
'gold' becomes 'au' (Au is the chemical symbol for gold).
'female' becomes 'hen' (hen is a kind of female).
'found in' means one lot of letters goes inside another.
'loft' becomes 'attic' (synonyms).
'not the first' means to remove the first letter.
'attic' with its initial letter taken away is 'ttic'.
'hen' placed inside 'ttic' is 'thentic'.
'au'+'thentic'='AUTHENTIC'
(Other definitions for authentic that I've seen before include "trustworthy" , "Genuine, not a copy" , "24 [LEGIT]" , "Ian, the cut is genuine" , "reliable" .)