Judge meets up with European (6)
I believe the answer is:
esteem
'judge' is the definition.
(I know that esteem is a more specific form of the action believe)
'meets up with european' is the wordplay.
'up with' indicates anagramming the letters (letters get chucked up).
'european' becomes 'E' (abbreviation e.g. EU).
'meets' anagrammed with 'e' can make 'ESTEEM'.
(Other definitions for esteem that I've seen before include "Revere(nce)" , "Admiration, regard" , "Value highly" , "gain respect" , "High opinion, great respect" .)