Tom, short-listed? (3)

I believe the answer is:

cat

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'tom' is the definition.
(a tom is a male cat)

I cannot understand how the rest of the clue works.

(Other definitions for cat that I've seen before include "Feline mammal" , "Animal (domesticated or wild)" , "Pussy" , "one's pyjamas? They're an excellent thing" , "Animal - one with nine tails!" .)

I've seen this clue in the Evening Standard.

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