Good man! Steak and French tart (8)
I believe the answer is:
strumpet
'tart' is the definition.
(thesaurus)
'good man steak and french' is the wordplay.
'good man' becomes 'st'.
'steak' becomes 'rump' (rump steak is a kind of steak).
'and french' becomes 'et' ('and' in the French language).
'st'+'rump'+'et'='STRUMPET'
(Other definitions for strumpet that I've seen before include "Lady of disrepute" , "... unlike her!" , "promiscuous, lady" , "call girl" , "Trumpets for loose woman" .)