Fierce feline (4)
I believe the answer is:
lion
'fierce feline' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lion that I've seen before include "Buddhist scripture; Sanskrit rule" , "Large predatory feline" , "one showing unusual courage?" , "King of the forest" , "Cowardly visitor in Oz" .)