Ugly coup takes in the French Nationalist going to Spain with great wealth (8)
I believe the answer is:
opulence
'great wealth' is the definition.
(I've seen this before)
'ugly coup takes in the french nationalist going to spain' is the wordplay.
'ugly' is an anagram indicator (an ugly or wrong form of the letters).
'takes in' means one lot of letters goes inside another.
'the french nationalist going' becomes 'len' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'to spain' becomes 'e' (abbreviation for Espana).
'coup' is an anagram of 'opuc'.
'opuc' placed around 'len' is 'opulenc'.
'opulenc'+'e'='OPULENCE'
'with' is the link.
Can you help me to learn more?
(Other definitions for opulence that I've seen before include "State of great prosperity" , "Open clue? (anag)" , "Impressive richness" , "Plenty" , "Fortune" .)