Oppose authority in there below (5)
I believe the answer is:
rebel
'oppose authority' is the definition.
(I've seen this before)
'in there below' is the wordplay.
'in' says the answer is hidden in the clue.
'REBEL' is hidden in the letters of 'there below'.
(Other definitions for rebel that I've seen before include "Flouter of authority" , "Unconventional type" , "Eg, Cade or Hereward" , "Mutineer, one who defies authority" , "Anti-establishment figure" .)