Meaning of “mine” - Learner’s Dictionary

mine

pronoun us uk /maɪn/
Extra Examples
She's a business associate of mine.I borrowed them from a friend of mine.Her views on raising children conflict with mine.His parents were rich, whereas mine had to struggle.The house next to mine is up for sale.

A2 the things that belong or relate to the person who is speaking or writing:

I borrowed them from a friend of mine.
"Whose book is this?" "It's mine."
Can I use your pen? Mine's not working.

(Definition of “mine pronoun” from the Cambridge Learner’s Dictionary © Cambridge University Press)