Giving thought to the idea The Ring is revolting (10)

I believe the answer is:

theorising

I'm a little stuck... Click here to teach me more about this clue!

'giving thought to the idea' is the definition.
I can't tell whether this definition defines the answer.

'the ring is revolting' is the wordplay.
'ring' becomes 'o'.
'is revolting' becomes 'rising' (I've seen this before).
'the'+'o'+'rising'='THEORISING'

Can you help me to learn more?

(Other definitions for theorising that I've seen before include "indulging in speculation" , "In speculative activity" , "coming up with ideas?" .)

I've seen this clue in the Irish Times and the Irish Times (Crosaire).

Want a hint initially instead of a full solution? Install my app