Go stone the Italian radical word maker (9)
I believe the answer is:
neologist
'radical word maker' is the definition.
The definition suggests a singular noun which matches the answer.
'go stone the italian' is the wordplay.
I cannot really see how this works, but
'stone' could be 'st' (abbreviation) and 'st' is present in the answer.
'italian' could be 'i' (abbreviation for Italian) and 'i' is found within the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for neologist that I've seen before include "One coining new words" , "Coiner" .)