Money is wonderful (7)
I believe the answer is:
capital
This clue is a double definition.
'money' is the first definition.
(I've seen this before)
'wonderful' is the second definition.
'is' acts as a link.
(Other definitions for capital that I've seen before include "savings" , "Havana, say" , "Wealth; main city" , "source of profit" , "Topping" .)