Big cat doorman skinned (5)
I believe the answer is:
ounce
'big cat' is the definition.
(ounce is a kind of big cat)
'doorman skinned' is the wordplay.
'doorman' becomes 'bouncer' (security guard stationed at a door).
'skinned' means to look at the middle letters.
The middle letters of 'bouncer' are 'OUNCE'.
(Other definitions for ounce that I've seen before include "Snow-leopard" , "16 for a pound" , "Weight; big cat" , "Small unit of weight" , "Jaguar" .)