"Cats" actor McKellen (3)
I believe the answer is:
ian
'cats actor mckellen' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for ian that I've seen before include "- Fleming (James Bond)" , "- McEwan, Eng. writer" , "The familar Dr Paisley" , "- - Wallace (baritone)" , "- Botham, cricketer" .)