Flair giving Peter pain (7)
I believe the answer is:
panache
'flair' is the definition.
('panache' can be a synonym of 'flair')
'giving peter pain' is the wordplay.
'giving' is a charade indicator (letters next to each other).
'peter' becomes 'pan' (I've seen this in other clues).
'pain' becomes 'ache' (ache is a kind of pain).
'pan' put next to 'ache' is 'PANACHE'.
(Other definitions for panache that I've seen before include "Flamboyant self-assurance" , "Distinctive elegance" , "Flamboyant confidence" , "Swagger; theatricality" , "Swagger, grand manner" .)