Fizzle (out) (3)
I believe the answer is:
die
'fizzle out' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for die that I've seen before include "Depart with engraved stamp" , "one proverbially straight" , "A device used for casting metal" , "One of a pair of dice" , "One spotted" .)