schoolmate
词根词缀：
bedmate n. 同床的人
bed 床 + mate 人 → 同床的人
flatmate n. 合住一套公寓的人
flat 公寓 + mate 人 → 合住一套公寓的人
playmate n. 玩伴；游戏伙伴
play 玩 + mate 人 → 玩伴；游戏伙伴
schoolmate n. 校友
school 学校 + mate 人 → 校友
shipmate n. 同船旅客；同船船员
ship 船 + mate 人 → 同船旅客；同船船员
teammate n. 队友
team 队伍 + mate 人 → 队友
数据来源：新东方英语词汇速记大全
相关例句：
It looks as if my schoolmate in shanghai find the information all about exam in her best.
看来我上海的同学尽她的努力找了所有的资料。
My father still keeps in touch with his old schoolmate.
我父亲仍和他的老同学保持联系。
Mary's brother is my schoolmate, but two years senior to my grade.
玛丽的哥哥跟我是校友，只是比我高两届。
Some months later I was joined by a roommate, an American schoolmate of mine who intended to stay a weekend and ended up finding a job and staying for more than a year.
几个月以后，我添了一位新室友。他是我在美国的同学，原本打算来过个周末，结果却找了份工作，在这里住了一年多。
At first we were bus mate, and schoolmate too.
最初，我们只是同学，常常在校车上碰面。
She is our middle schoolmate Xiao Jing.
她是我的中学同学小静。