noun
class president; head class representative
The student elected to lead a homeroom class in Japanese schools, often responsible for coordinating with teachers and representing the class at meetings.
彼は学級委員長に選ばれた。
He was elected class president.
学級委員長として、クラスの意見をまとめる役割がある。
As the head class representative, you have the role of gathering the class's opinions.
Compound of 学級 (がっきゅう, 'class') + 委員長 (いいんちょう, 'committee chairperson').