What is Chair ?
Chair is (noun) 1. a piece of furniture which you can sit on, with a back He pulled up a chair and started to write. These dining-room chairs are very hard. 2. the person who is in charge of a meeting Please address all your comments to the chair. in the chair the position of being in charge of a meeting Mrs Smith was in the chair. Mr Jones took the chair Mr Jones was in charge of the meeting 3. the position of professor at a university He has been appointed to the chair of English.(verb) to take charge of a meeting The meeting was chaired by Mrs Smith.
source: Easier English, Student Dictionary Upper Intermediate Level