Stress shown by European? Pass him nervously (8)
I believe the answer is:
emphasis
'stress' is the definition.
('emphasis' can be a synonym of 'stress')
'european? pass him nervously' is the wordplay.
'european?' becomes 'e' (abbreviation e.g. EU).
'nervously' is an anagram indicator.
'pass'+'him'='passhim'
'passhim' is an anagram of 'mphasis'.
'e'+'mphasis'='EMPHASIS'
'shown by' acts as a link.
(Other definitions for emphasis that I've seen before include "Stress or significance" , "Stress laid on, eg, words" , "Intensity of expression" , "Stress, accent" , "Weight" .)