European proposal's a sensation (7)
I believe the answer is:
emotion
'a sensation' is the definition.
(thesaurus)
'european proposal's' is the wordplay.
'european' becomes 'E' (abbreviation e.g. EU).
'proposal' becomes 'motion' (proposal at a meeting).
'e'+'motion'='EMOTION'
(Other definitions for emotion that I've seen before include "eg Anger, fear, joy" , "sense" , "Feeling - sentiment" , "Passion" , "Mental agitation" .)