Scoundrel runs half of La Scala? Not entirely (6)
I believe the answer is:
rascal
'scoundrel' is the definition.
(rascal is a kind of scoundrel)
'runs half of la scala? not entirely' is the wordplay.
'runs' becomes 'r' (cricket abbreviation).
'half of' indicates taking half.
'not entirely' means to remove the last letter.
'la' cut in half is 'a'.
'scala' with its final letter taken away is 'scal'.
'r'+'a'+'scal'='RASCAL'
(Other definitions for rascal that I've seen before include "Impudent person" , "Knave, rogue" , "wretch" , "A mischievous and maybe dishonest person" , "not one to be admired" .)