Snow leopards (6)
I believe the answer is:
ounces
'snow leopards' is the definition.
('ounce' can be a synonym of 'snow leopard')
This is the entire clue.
(Other definitions for ounces that I've seen before include "Sixteen to a pound" , "There are 12 in a pound" , "Animals" , "Light weights in UNESCO" , "Sixteen of these to a lb" .)