Question

what is the abstract noun of die

Answer 1

The abstract noun form for the verb 'to die' is the gerund dying. 
A related abstract noun form is death. 

The word 'die' is a concrete noun form for one of a set of dice; a tool used to imprint materials; a implement for cutting or shaping metal.

Answer 2

Abstract noun denotes immeasurable idea, state or quality, such as emotions, danger, truth, and more.

In the given query, we are asked about the abstract noun of the verb "die". Moreover, the answer is: "Death." This is an abstract noun which reveals the fact or idea of dying, or say "end of life of any living being."