What is the plural noun for shiny?

There isn't a plural noun for "shiny." "Shiny" is an adjective, describing something that is bright and reflecting light. It doesn't have a plural form because it's not a noun.

To make something plural, you would need a noun that it modifies. For example:

* Shiny object: This is a singular noun.

* Shiny objects: This is the plural form.