furnace vs athanor

furnace and athanor both are nouns.

Word	Noun	Adjective	Verb	Adverb
furnace	Yes	No	No	No
athanor	Yes	No	No	No

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

furnace: an enclosed chamber in which heat is produced to heat buildings, destroy refuse, smelt or refine ores, etc.
athanor: a furnace that feeds itself so as to maintain a uniform temperature; used by alchemists

furnace (noun)	athanor (noun)
an enclosed chamber in which heat is produced to heat buildings, destroy refuse, smelt or refine ores, etc.	a furnace that feeds itself so as to maintain a uniform temperature; used by alchemists