What is the term for a word that describes nouns and pronouns?

The term for a word that describes nouns and pronouns is adjective.

Here's why:

* Adjectives modify nouns and pronouns, providing more information about them.

* Nouns are words that name people, places, things, or ideas.

* Pronouns are words that replace nouns.

For example:

* The big dog (big is an adjective modifying the noun "dog")

* He is happy (happy is an adjective modifying the pronoun "he")