Work with Universal, fast becoming rich (7)
I believe the answer is:
opulent
'rich' is the definition.
(similar in meaning)
'work with universal fast' is the wordplay.
'work' becomes 'op' (abbreviation for opus).
'with' means one lot of letters go next to another.
'universal' becomes 'U' (film certificate).
'fast' becomes 'lent' (Lent is a period of fasting in Christianity).
'op'+'u'+'lent'='OPULENT'
'becoming' acts as a link.
(Other definitions for opulent that I've seen before include "Wealthy, luxurious" , "Wealthy, possessing riches" , "indicating wealth" , "Wealthy, got lots of money" , "Moneyed" .)