Great solving! (8)
I believe the answer is:
cracking
This clue is a double definition.
'great' is the first definition.
(I know that great can be written as cracking)
'solving' is the second definition.
(e.g. cracking a code)
(Other definitions for cracking that I've seen before include "Excellent; fracturing" , "very fast" , "great!" , "Wonderful" , "failing" .)