Nice men struggling with European for prominence (8)
I believe the answer is:
eminence
'prominence' is the definition.
(thesaurus)
'nice men struggling with european' is the wordplay.
'struggling with' is an anagram indicator.
'european' becomes 'E' (abbreviation e.g. EU).
'nice'+'men'='nicemen'
'nicemen' anagrammed with 'e' gives 'EMINENCE'.
'for' acts as a link.
(Other definitions for eminence that I've seen before include "Note - height" , "High prestige for cardinal?" , "cardinal's address" , "High status importance" , "Esteem" .)