Mountain cat (6)
(Other definitions for cougar that I've seen before include "Big cat" , "Large American feline" , "North American mountain lion" , "North American puma" , "N American mountain lion, puma" .)
'mountain cat' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for lynx that I've seen before include "European wild cat" , "Bobcat" , "Member of the cat family" , "Wild cat -- text browser" , "one with exceptionally good sight" .)
(Other definitions for puma that I've seen before include "International rugby player" , "American wildcat" , "Large Am. wild cat" , "American wild cat" , "Large mountain cat" .)