Least feral (6)
I believe the answer is:
tamest
'least feral' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for tamest that I've seen before include "Least wild, most domesticated" , "Meekest or least wild" , "Least exciting" , "Most docile" , "Most restrained or quiet" .)