Pelt round after one so wildly (7)
I believe the answer is:
furioso
'wildly' is the definition.
Both the definition and answer are adverbs.
Maybe there's a link between them I don't understand?
'pelt round after one so' is the wordplay.
'pelt' becomes 'fur' (synonyms).
'round after one' becomes 'io' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'fur'+'io'+'so'='FURIOSO'
Can you help me to learn more?
(Other definitions for furioso that I've seen before include "(Musical instruction) with force and energy -- Rio's UFO (anag)" , "going wild in bars" .)