Bob runs the committee without leader from party (6)
I believe the answer is:
'bob' is the definition.
(bob is a type of hairdo)
'runs the committee without leader from party' is the wordplay.
'runs the committee' becomes 'hai' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'without leader' means to remove the first letter.
'from' becomes 'fr' (abbreviation).
'party' becomes 'do' (do is a kind of party).
'fr' with its initial letter taken off is 'r'.
'hai'+'r'+'do'='HAIRDO'
Can you help me to learn more?
(Other definitions for hairdo that I've seen before include "capital arrangement" , "Arrangement of locks" , "Cut and set" , "Coiffure (colloq.)" , "Bob, perhaps" .)