Learned wife is European (4)
I believe the answer is:
wise
'learned' is the definition.
(I've seen this in another clue)
'wife is european' is the wordplay.
'wife' becomes 'w' (abbreviation).
'european' becomes 'E' (abbreviation e.g. EU).
'w'+'is'+'e'='WISE'
(Other definitions for wise that I've seen before include "Showing sagacity" , "Clever" , "Experienced, knowing" , "Prudent" , "Astute" .)