Greek leader soon accepts brave maiden (9)
I believe the answer is:
agamemnon
'greek leader' is the definition.
(I've seen this before)
'soon accepts brave maiden' is the wordplay.
'soon' becomes 'anon' (synonyms).
'accepts' is an insertion indicator.
'brave' becomes 'game' (similar in meaning).
'maiden' becomes 'm' (cricket abbreviation).
'game'+'m'='gamem'
'anon' enclosing 'gamem' is 'AGAMEMNON'.
(Other definitions for agamemnon that I've seen before include "mythological king" , "Leader of Greeks in Trojan War" , "Greek leader in the Trojan War" , "Greek commander against Troy" , "Fabled king soon" .)