Wealthy work fast after university (7)
I believe the answer is:
opulent
'wealthy' is the definition.
(opulent means extravagantly wealthy)
'work fast after university' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'fast' becomes 'lent' (Lent is a period of fasting in Christianity).
'after' means one lot of letters go next to another.
'university' becomes 'U' (abbreviation as in UMass).
'lent' put after 'u' is 'ulent'.
'op'+'ulent'='OPULENT'
(Other definitions for opulent that I've seen before include "'Rich, sumptuous (7)'" , "Wealthy, rich" , "Wealthy or lavish" , "magnificent" , "Let up on, being wealthy" .)