1. (委员会、组织机构的)主席;(公司)总裁
The chairman of a committee, organization, or company is the head of it.

2. (会议、辩论的)主持人，主席
The chairman of a meeting or debate is the person in charge, who decides when each person is allowed to speak.

1. the officer who presides at the meetings of an organization

e.g. address your remarks to the chairperson

Synonym: presidentchairwomanchairchairperson