Uncle's cat? (3)
I believe the answer is:
tom
This clue is a double definition.
'uncle's' is the first definition.
(as in the novel Uncle Tom's Cabin)
'cat?' is the second definition.
(a tom is a male cat)
(Other definitions for tom that I've seen before include "Boy running off with pig" , "Edgar's Poor disguise (Lear)" , "Pig-stealing piper's son" , "famous schoolboy" , "Queen's mate" .)