Little-pigs complement (5)
I believe the answer is:
three
'little-pigs complement' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for three that I've seen before include "So many 12s today" , "Sixth root of seven hundred and twenty nine" , "Number of strikes before you're out" , "Number of blind mice" , "trilogy" .)