Apt anagram of "vile" (4)
I believe the answer is:
evil
'apt anagram of vile' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for evil that I've seen before include "Malignant" , "Very wicked or bad" , "Excellent" , "Morally objectionable behavior" , "Live kind of badness" .)