Act confused pet (3)
I believe the answer is:
cat
'pet' is the definition.
(I've seen this in another clue)
'act confused' is the wordplay.
'confused' is an anagram indicator.
'act' with letters rearranged gives 'CAT'.
(Other definitions for cat that I've seen before include "Moggy" , "Feline - whip" , "eg Leopard" , "Eg, tiger, lion" , "Sailor's whip with nine knotted strands" .)