To conform absolutely (7)
I believe the answer is:
'absolutely' is the definition.
'to conform' is the wordplay.
'conform' becomes 'tally' (I can't justify this - if you can you should give a lot more credence to this answer).
Can you help me to learn more?
(Other definitions for totally that I've seen before include "without reservation" , "Altogether" , "Completely, entirely" , "in every respect" , "Absolutely" .)