refractory vs fireclay

refractory and fireclay both are nouns.

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

refractory (noun)	fireclay (noun)
lining consisting of material with a high melting point; used to line the inside walls of a furnace	a heat-resistant clay

refractory (adjective)	fireclay (adjective)
stubbornly resistant to authority or control
temporarily unresponsive or not fully responsive to a process or stimulus
not responding to treatment