Question

definition of pronoun...........

Answer 1

A pronoun is a word that is used instead of a noun or noun phrase. Pronouns refer to either a noun that has already been mentioned or to a noun that does not need to be named specifically.

Answer 2

A pronoun is a word used instead of a noun  

for example  

John is absent because he is I'll.

A pronoun is a word used instead of a noun. i.e. I, we, you, he, she, it.