ETYM Old Eng. chaiere, chaere, Old Fren. chaiere, chaere, French chaire pulpit, from Latin cathedra chair, armchair, a teacher's or professor's chair, Greek cata down + hedra seat, hizein to sit, akin to Eng. sit. Related to Sit, Cathedral, chaise.
A seat for one person, with a support for the back.
(traditionally called chairman but more commonly called chair or chairperson today) individual who controls (chairs) a meeting. It is the responsibility of the chair to ensure that an agenda for the meeting is prepared and that the agenda is discussed. A good chair will ensure that everyone at the meeting can make relevant contributions while at the same time carrying the meeting forward so that all points on the agenda are discussed within the limited time set for the meeting. A chair of a company chairs meetings of the board of directors and is in overall charge of the company.

To act or preside as chair, as of an academic department in a university; SYN. chairman.