What is the collective noun for nouns?

There isn't a single, universally accepted collective noun for "nouns".

However, you could use these options depending on the context:

General:

* A set of nouns

* A group of nouns

* A collection of nouns

* A list of nouns

* A lexicon of nouns

More specific:

* A vocabulary of nouns

* A thesaurus of nouns

* A dictionary of nouns

* A nomenclature of nouns (especially if referring to technical terms)

Ultimately, the best option will depend on the specific situation and the desired tone.