seat vs chair

seat and chair both are nouns.

Word	Noun	Adjective	Verb	Adverb
seat	Yes	No	Yes	No
chair	Yes	No	Yes	No

As nouns, chair is a hyponym of seat; that is, chair is a word with a more specific, narrower meaning than seat:

seat: any support where you can sit (especially the part of a chair or bench etc. on which you sit)
chair: a particular seat in an orchestra

As nouns, chair is a hyponym of seat; that is, chair is a word with a more specific, narrower meaning than seat:

seat (noun)	chair (noun)
any support where you can sit (especially the part of a chair or bench etc. on which you sit)	the position of professor
furniture that is designed for sitting on	a seat for one person, with a support for the back
the cloth covering for the buttocks	an instrument of execution by electrocution; resembles an ordinary seat for one person
a part of a machine that supports or guides another part	a particular seat in an orchestra
the legal right to sit as a member in a legislative or similar body	the officer who presides at the meetings of an organization
the fleshy part of the human body that you sit on
a center of authority (as a city from which authority is exercised)
a space reserved for sitting (as in a theater or on a train or airplane)
the location (metaphorically speaking) where something is based

seat (verb)	chair (verb)
show to a seat; assign a seat for	preside over
place or attach firmly in or on a base	act or preside as chair, as of an academic department in a university
place in or on a seat
provide with seats
put a seat on a chair
place ceremoniously or formally in an office or position
be able to seat