'A very European' fury? That's mean (7)
I believe the answer is:
average
'mean' is the definition.
(I know that mean can be written as average)
'a very european fury?' is the wordplay.
'very' becomes 'v' (abbreviation).
'european' becomes 'E' (abbreviation e.g. EU).
'fury?' becomes 'rage' (synonyms).
'a'+'v'+'e'+'rage'='AVERAGE'
'that's' acts as a link.
(Other definitions for average that I've seen before include "building society customer loses capital over time" , "Usual - mediocre - mean" , "Mediocre - medium" , "nothing special" , "representative figure?" .)