Rebel is concealing name, demanding attention (9)
I believe the answer is:
insurgent
'rebel' is the definition.
(I know that rebel can be written as insurgent)
'is concealing name demanding attention' is the wordplay.
'concealing' is an insertion indicator.
'name' becomes 'n' (common abbreviation e.g. on forms).
'demanding attention' becomes 'urgent'.
'is' placed around 'n' is 'ins'.
'ins'+'urgent'='INSURGENT'
(Other definitions for insurgent that I've seen before include "rising" , "Unresting like a rebel" , "freedom fighter" , "Rebel, revolutionary" , "Revolting" .)