Question

Is dust a metonymy for death?

Answer 1

Yes

Explanation:

Metonymy is a literary device where we replace a word out for one that is closely associated with it.

http://literarydevices.net/metonymy/

Dust is certainly a word that is used as a metonymy for death. It shows up in this phrase we often hear at funerals:

Ashes to ashes, dust to dust