noun
fellow alumnus; graduate of the same school; former schoolmate
Refers to someone who attended the same school, typically at the same time or as part of the same graduating class. Often used in reunion contexts.
彼は私の大学の同窓生です。
He is a fellow alumnus from my university.
同窓生との再会を楽しみにし
I'm looking forward to reuniting with my former schoolmates.