Feral (4)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
wild
'feral' is the definition.
(similar in meaning)
This is all the clue.
(Other definitions for wild that I've seen before include "Not tamed" , "Fierce" , "Not domesticated" , "Born Free?" , "Feral - crazy" .)