writing arm vs tablet-armed chair

writing arm and tablet-armed chair both are nouns.

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

writing arm (noun)	tablet-armed chair (noun)
an arm of a tablet-armed chair; widened to provide a writing surface	a chair with an arm that has been widened for writing