President
Part of speech: noun
Definition: The head of state of a republic, a representative democracy and sometimes (in cases of constitutional violations) a dictatorship. The primary leader of a corporation. Not to be confused with CEO, which is a related but separate position that is sometimes held by a different person.
Example sentence: People have got to know whether or not their president is a crook. Well, I'm not a crook. I earned everything I've got.
Chairman
Part of speech: noun
Definition: A person presiding over a meeting.The head of a corporate or governmental board of directors, a committee, or other formal entity.Someone whose job is to carry people in a portable chair, sedan-chair, or similar conveyance.
Example sentence: I flunked my exam for university two times before I was accepted by what was considered my city's worst university, Hangzhou Teachers University. I was studying to be a high school English teacher. In my university, I was elected student chairman and later became chairman of the city's Students Federation.