Wind up European man of wisdom (4)
I believe the answer is:
sage
'man of wisdom' is the definition.
(I've seen this before)
'wind up european' is the wordplay.
'wind' becomes 'gas' (synonyms).
'up' says the letters should be written in reverse (in down clue: letters go upwards).
'european' becomes 'E' (abbreviation e.g. EU).
'gas' reversed gives 'sag'.
'sag'+'e'='SAGE'
(Other definitions for sage that I've seen before include "Feature of herb garden" , "A herb or a guru" , "Herb; wise person" , "Fragrant herb or wise man" , "Fragrant herb having wisdom" .)