Make up for the bad hairdo (6)
I believe the answer is:
offset
'make up for' is the definition.
(I've seen this before)
'the bad hairdo' is the wordplay.
'the bad' becomes 'off' (I've seen this before).
'hairdo' becomes 'set' (I can't explain this - if you can you should give a lot more credence to this answer).
'off'+'set'='OFFSET'
Can you help me to learn more?
(Other definitions for offset that I've seen before include "Place out of line" , "Compensate for - printing method" , "Balance out" , "Counterbalance(d)" , "Compensation - printing process" .)