Feline's weight? (5)
I believe the answer is:
ounce
This clue is a double definition.
'feline's' is the first definition.
(ounce is a kind of feline)
'weight?' is the second definition.
(I know that ounce is a type of troy unit)
(Other definitions for ounce that I've seen before include "one of a number in the pound" , "Twelfth of a pound" , "Carnivore" , "Small imperial weight" , "Small amount (of old pound)" .)