Soundly beaten but sadly not cured (8)
I believe the answer is:
trounced
'soundly beaten' is the definition.
'trounced' can be an answer for 'beaten' (thesaurus). I am not certain of the 'soundly' bit.
'sadly not cured' is the wordplay.
'sadly' indicates an anagram.
'not'+'cured'='notcured'
'notcured' anagrammed gives 'TROUNCED'.
'but' is the link.
Can you help me to learn more?
(Other definitions for trounced that I've seen before include "Defeated decisively" , "Not cured after receiving heavy beating" , "Beat hollow" , "Thrashed, beat heavily" .)