Rascal wandering and getting better (9)
I believe the answer is:
improving
'getting better' is the definition.
(I've seen this before)
'rascal wandering' is the wordplay.
'rascal' becomes 'imp' (synonyms).
'wandering' becomes 'roving' (synonyms).
'imp'+'roving'='IMPROVING'
'and' acts as a link.
(Other definitions for improving that I've seen before include "Recovering" , "Making better" , "Getting better" .)