Mockery scars a wretched maiden (7)
I believe the answer is:
sarcasm
'mockery' is the definition.
(I've seen this before)
'scars a wretched maiden' is the wordplay.
'wretched' indicates an anagram.
'maiden' becomes 'm' (cricket abbreviation).
'scars'+'a'='scarsa'
'scarsa' anagrammed gives 'sarcas'.
'sarcas'+'m'='SARCASM'
(Other definitions for sarcasm that I've seen before include "Ironical expression of scorn or contempt" , "Insulting lingo" , "insulting language" , "Cutting wit" , "Satirical and scornful remarks" .)