graphite vs plumbago

graphite and plumbago both are nouns.

Word	Noun	Adjective	Verb	Adverb
graphite	Yes	No	No	No
plumbago	Yes	No	No	No

As nouns, graphite and plumbago are synonyms defined as:

graphite and plumbago: used as a lubricant and as a moderator in nuclear reactors

Other synonyms of graphite include black lead.

graphite (noun)	plumbago (noun)
used as a lubricant and as a moderator in nuclear reactors	any plumbaginaceous plant of the genus Plumbago
	used as a lubricant and as a moderator in nuclear reactors