Jaguar’s annual check-up perhaps upset cat (3)

I believe the answer is:
tom
'cat' is the definition.
(a tom is a male cat)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for tom that I've seen before include "Repeated twice, this becomes an African drum" , "He is associated with Dick and Harry" , "Thumb" , "What Dick Whittington had" , "Boy - cat" .)
