Definition of chair

The noun chair has 5 senses? (first 2 from tagged texts)

(a seat for one person, with a support for the back; "he put his coat over the back of the chair and sat down")

(the position of professor; "he was awarded an endowed chair in economics")

(the officer who presides at the meetings of an organization; "address your remarks to the chairperson")

(an instrument of execution by electrocution; resembles an ordinary seat for one person; "the murderer was sentenced to die in the chair")

(a particular seat in an orchestra; "he is second chair violin")

The verb chair has 2 senses? (no senses from tagged texts)

(act or preside as chair, as of an academic department in a university; "She chaired the department for many years")

(preside over; "John moderated the discussion")