Chair

a seat, especially for one person, usually having four legs for support and a rest for the back and often having rests for the arms.
something that serves as a chair or supports like a chair:
The two men clasped hands to make a chair for their injured companion.
a seat of office or authority.
a position of authority, as of a judge, professor, etc.
the person occupying a seat of office, especially the chairperson of a meeting:
The speaker addressed the chair.
(in an orchestra) the position of a player, assigned by rank; desk:
first clarinet chair.
the chair, Informal. electric chair.
chairlift.
sedan chair.
(in reinforced-concrete construction) a device for maintaining the position of reinforcing rods or strands during the pouring operation.
a glassmaker’s bench having extended arms on which a blowpipe is rolled in shaping glass.
British Railroads. a metal block for supporting a rail and securing it to a crosstie or the like.
to place or seat in a chair.
to install in office.
to preside over; act as chairperson of:
to chair a committee.
British. to carry (a hero or victor) aloft in triumph.
to preside over a meeting, committee, etc.
get the chair, to be sentenced to die in the electric chair.
take the chair,

to begin or open a meeting.
to preside at a meeting; act as chairperson.

noun
a seat with a back on which one person sits, typically having four legs and often having arms
an official position of authority: a chair on the board of directors
the person chairing a debate or meeting: the speaker addressed the chair
a professorship: the chair of German
(railways) an iron or steel cradle bolted to a sleeper in which the rail sits and is locked in position
short for sedan chair
in the chair, chairing a debate or meeting
take the chair, to preside as chairman for a meeting, etc
the chair, an informal name for electric chair
verb (transitive)
to preside over (a meeting)
(Brit) to carry aloft in a sitting position after a triumph or great achievement
to provide with a chair of office
to install in a chair
n.

early 13c., chaere, from Old French chaiere “chair, seat, throne” (12c.; Modern French chaire “pulpit, throne;” the more modest sense having gone since 16c. with variant form chaise), from Latin cathedra “seat” (see cathedral).

Figurative sense of “authority” was in Middle English, of bishops and professors. Meaning “office of a professor” (1816) is extended from the seat from which a professor lectures (mid-15c.). Meaning “seat of a person presiding at meeting” is from 1640s. As short for electric chair from 1900.
v.

mid-15c., “install in a chair or seat” (implied in chairing), from chair (n.); meaning “preside over” (a meeting, etc.) is attested by 1921. Related: Chaired.
see: musical chairs