schoolmate
nounUK /ˈskuːlmeɪt/
US /ˈskuːlmeɪt/
A schoolmate is a person who goes to the same school as you.
My schoolmate helped me find my classroom on the first day.
OTHER MEANINGS
2. A person you knew during your school years, even if you were not close friends.
I ran into an old schoolmate at the grocery store.
3. A fellow student in the same school but not necessarily the same class.
He and his schoolmates played football after lessons.
4. A companion or associate from one's school days.
She invited several schoolmates to her birthday party.