emetic vs nauseant

emetic and nauseant both are nouns.

Word	Noun	Adjective	Verb	Adverb
emetic	Yes	No	No	No
nauseant	Yes	No	No	No

As nouns, emetic and nauseant are synonyms defined as:

Other synonyms of emetic include vomit, vomitive.

emetic (noun)	nauseant (noun)
a medicine that induces nausea and vomiting	a medicine that induces nausea and vomiting