Lady left with gold, protected by criminal agent (8)
I believe the answer is:
florence
'lady' is the definition.
'left with gold protected by criminal agent' is the wordplay.
'left' becomes 'l' (common abbreviation).
'with' says to put letters next to each other.
'gold' becomes 'or' ('or' is the heraldic name for gold).
'protected by' indicates putting letters inside.
'criminal agent' becomes 'fence' (a fence handles stolen goods).
'l'+'or'='lor'
'lor' placed into 'fence' is 'FLORENCE'.
(Other definitions for florence that I've seen before include "Medicis' Tuscan city" , "Nightingale possibly" , "Ms Nightingale in great Italian city" , "Angel of the reclining (anag) -- nurse" , "famous Italian city" .)