What is the collective noun for hats?

There isn't a commonly used collective noun specifically for hats. However, you could use some general collective nouns that fit depending on the context:

* A collection of hats

* A variety of hats

* A rack of hats

* A display of hats

* A pile of hats

You could also get creative and use a noun that describes the specific type of hats:

* A crown of sombreros

* A stack of fedoras

* A regiment of top hats

Ultimately, the best collective noun will depend on the specific situation and the type of hats you are talking about.