Greet the villain (3)
I believe the answer is:
boo
'greet the villain' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for boo that I've seen before include "Make one's dislike heard" , "Startling utterance" , "I don't like that!" , "Surprising exclamation" , "Sound made to show disapproval or contempt" .)