caustic vs vitriolic

caustic is a noun but vitriolic is not a noun.

Word	Noun	Adjective	Verb	Adverb
caustic	Yes	Yes	No	No
vitriolic	No	Yes	No	No

As adjectives, caustic and vitriolic are synonyms defined as:

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

Other synonyms of caustic include corrosive, erosive, mordant.

As adjectives, caustic and vitriolic are synonyms defined as:

Other synonyms of caustic include acerb, acerbic, acid, acrid, bitter, blistering, sulfurous, sulphurous, virulent.

caustic (noun)	vitriolic (noun)
the envelope of light rays reflected or refracted by a curved surface or object
any chemical substance that burns or destroys living tissue

caustic (adjective)	vitriolic (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
harsh or corrosive in tone	harsh or corrosive in tone