emetic vs ipecac

emetic and ipecac both are nouns.

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

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

emetic: a medicine that induces nausea and vomiting
ipecac: a medicinal drug used to evoke vomiting (especially in cases of drug overdose or poisoning)

Other hyponyms of emetic include dry mustard, powdered mustard.

emetic (noun)	ipecac (noun)
a medicine that induces nausea and vomiting	a medicinal drug used to evoke vomiting (especially in cases of drug overdose or poisoning)