It rises above half-German feline (5)
I believe the answer is:
tiger
'feline' is the definition.
(I know that tiger is a type of big cat)
'it rises above half-german' is the wordplay.
'rises' shows that the letters should be reversed in order.
'above' is a charade indicator (letters next to each other) (in a down clue, some letters go above others).
'half' suggests halving the letters.
'it' in reverse letter order is 'ti'.
'german' cut in half is 'ger'.
'ti'+'ger'='TIGER'
(Other definitions for tiger that I've seen before include "Formidable competitor" , "Fierce feline" , "___ Woods, golfer" , "Carnivorous large cat" , "- - Woods (golf)" .)