Headgear graduate used during performance (6)
I believe the answer is:
turban
'headgear' is the definition.
(I know that turban is a type of headgear)
'graduate used during performance' is the wordplay.
'graduate' becomes 'BA' (someone with a Bachelor of Arts degree).
'used during' means one lot of letters goes inside another.
'performance' becomes 'turn' (turn is a kind of performance).
'ba' going inside 'turn' is 'TURBAN'.
(Other definitions for turban that I've seen before include "Nut bar (anag.)" , "Cloth wound around the head" , "Cloth worn as headdress by Sikh" , "But ran out for the headdress" , "Sikh headgear" .)