Make public: “Ann’s lost weight” (5)
I believe the answer is:
ounce
'weight' is the definition.
(ounce is a kind of weight)
'make public ann's lost' is the wordplay.
'make public' becomes 'announce' (I've seen this before).
'lost' suggests deleting specific letters.
'announce' with 'ann' taken out is 'OUNCE'.
(Other definitions for ounce that I've seen before include "Unit of weight - snow leopard" , "Unit of weight; cat" , "One sixteenth of a pound" , "Panther, perhaps" , "Oz" .)