Is returning to circus in rebellion (6)
I believe the answer is:
rising
'rebellion' is the definition.
(I know that rebellion can be written as rising)
'is returning to circus in' is the wordplay.
'returning' is a reversal indicator.
'to circus' becomes 'ring' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' indicates putting letters inside.
'is' back-to-front is 'si'.
'si' put within 'ring' is 'RISING'.
Can you help me to learn more?
(Other definitions for rising that I've seen before include "Sloping up; rebellion" , "Insurrection" , "Revolt; increasing" , "In the ascendant" , "A revolt; getting up" .)