A word that substitutes for a previously specified noun or phrase is known as what?

A word that substitutes for a previously specified noun or phrase is called a pronoun.

Here's why:

* Pronoun: A word that replaces a noun or noun phrase to avoid repetition and make writing more concise.

For example:

* Noun: "The cat"

* Pronoun: "It"

Instead of saying "The cat sat on the mat, and the cat ate the food," you could say "The cat sat on the mat, and it ate the food."