One sixteenth of a pound (5)
I believe the answer is:
ounce
'one sixteenth of a pound' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ounce that I've seen before include "weight? Surely not" , "scrap" , "Small quantity - snow leopard" , "one of a number in the pound" , "not weighing very much" .)