erosive vs mordant

erosive is not a noun while mordant is a noun.

Word	Noun	Adjective	Verb	Adverb
erosive	No	Yes	No	No
mordant	Yes	Yes	No	No

As adjectives, erosive and mordant are synonyms defined as:

erosive and mordant: of a substance, especially a strong acid; capable of destroying or eating away by chemical action

Other synonyms of erosive include caustic, corrosive, vitriolic.

erosive (noun)	mordant (noun)
	a substance used to treat leather or other materials before dyeing; aids in dyeing process

erosive (adjective)	mordant (adjective)
of a substance, especially a strong acid; capable of destroying or eating away by chemical action	of a substance, especially a strong acid; capable of destroying or eating away by chemical action
wearing away by friction	harshly ironic or sinister