Rhode Island pop star with more money (6)
I believe the answer is:
richer
'with more money' is the definition.
(I've seen this before)
'rhode island pop star' is the wordplay.
'rhode island' becomes 'RI' (US postal abbreviation).
'pop star' becomes 'Cher' (American singer).
'ri'+'cher'='RICHER'
(Other definitions for richer that I've seen before include "More well-off" , "Having more wealth" , "More wealthy" , "With more money" , "Wealthier" .)