Cats to close unexpectedly (7)
I believe the answer is:
ocelots
'cats' is the definition.
(ocelot is a kind of cat)
'to close unexpectedly' is the wordplay.
'unexpectedly' is an anagram indicator.
'to'+'close'='toclose'
'toclose' anagrammed gives 'OCELOTS'.
(Other definitions for ocelots that I've seen before include "animals in the wild" , "Cats - cool set (anag)" , "Small leopards found in sole cot" , "Close to, oddly, the wildcats" .)