Snow leopard — unit of weight (5)
I believe the answer is:
ounce
This clue is a double definition.
'snow leopard' is the first definition.
(ounce is an alternative name for the snow leopard)
'unit of weight' is the second definition.
(I've seen this in another clue)
(Other definitions for ounce that I've seen before include "Enough to tip the scales" , "There are quite a few in the pound" , "16 for a pound" , "little weight" , "Unit of weight; cat" .)