See union member's revolting hairdo (6)
I believe the answer is:
mullet
'hairdo' is the definition.
(mullet is a type of hairdo)
'see union member's revolting' is the wordplay.
'see' becomes 'tell' (I am not sure about this - if you are sure you should believe this answer much more).
'union' becomes 'U' (common abbreviation as in 'Trades Union Congress').
'member' becomes 'm' (political abbreviation).
'revolting' shows that the letters should be reversed in order.
'tell'+'u'+'m'='tellum'
'tellum' reversed gives 'MULLET'.
Can you help me to learn more?
(Other definitions for mullet that I've seen before include "Starfish" , "swimmer" , "Fish - bad haircut" , "Barnet?" , "Fish; man's hair style" .)