Insult about European's manual dexterity (7)
I believe the answer is:
sleight
'manual dexterity' is the definition.
('sleight' can be a synonym of 'manual dexterity')
'insult about european's' is the wordplay.
'insult' becomes 'slight' (I've seen this before).
'about' means one lot of letters goes inside another.
'european' becomes 'e' (abbreviation e.g. EU).
'slight' enclosing 'e' is 'SLEIGHT'.
(Other definitions for sleight that I've seen before include "Trickery" , "Skilful deception" , "Manual dexterity" , "Dexterity (usually of hand)" , "craft" .)