tablet-armed chair vs chair

tablet-armed chair and chair both are nouns.

Word	Noun	Adjective	Verb	Adverb
tablet-armed chair	Yes	No	No	No
chair	Yes	No	Yes	No

As nouns, chair is a hypernym of tablet-armed chair; that is, chair is a word with a broader meaning than tablet-armed chair:

tablet-armed chair (noun)	chair (noun)
a chair with an arm that has been widened for writing	the position of professor
	a seat for one person, with a support for the back
	an instrument of execution by electrocution; resembles an ordinary seat for one person
	a particular seat in an orchestra
	the officer who presides at the meetings of an organization

tablet-armed chair (verb)	chair (verb)
	preside over
	act or preside as chair, as of an academic department in a university