refractory vs stubborn

refractory is a noun but stubborn is not a noun.

Word	Noun	Adjective	Verb	Adverb
refractory	Yes	Yes	No	No
stubborn	No	Yes	No	No

As adjectives, refractory and stubborn are synonyms defined as:

refractory (noun)	stubborn (noun)
lining consisting of material with a high melting point; used to line the inside walls of a furnace

refractory (adjective)	stubborn (adjective)
stubbornly resistant to authority or control	tenaciously unwilling or marked by tenacious unwillingness to yield
temporarily unresponsive or not fully responsive to a process or stimulus	not responding to treatment
not responding to treatment