Wicked, terrible lie about Victor (4)
I believe the answer is:
evil
'wicked' is the definition.
(similar in meaning)
'terrible lie about victor' is the wordplay.
'terrible' indicates an anagram.
'about' indicates putting letters inside.
'victor' becomes 'V' (phonetic alphabet: alpha, bravo, charlie etc.).
'lie' anagrammed gives 'eil'.
'eil' enclosing 'v' is 'EVIL'.
(Other definitions for evil that I've seen before include "Extremely bad" , "source of harm" , "Morally objectionable behavior" , "Live badly for badness" , "Maleficent" .)