the chairperson of a committee — the person who leads and moderates meetings and represents the committee.
新しい委員長が来月の総会で正式に発表される。
The new chairperson will be officially announced at next month's general meeting.
委員長として会議を円滑に進める責任がある。
As chairperson, he is responsible for running the meeting smoothly.
学級委員長に立候補する学生が増えた。
More students have run for class representative (class chairperson).