polymyxin vs antibiotic

polymyxin and antibiotic both are nouns.

Word	Noun	Adjective	Verb	Adverb
polymyxin	Yes	No	No	No
antibiotic	Yes	Yes	No	No

As nouns, antibiotic is a hypernym of polymyxin; that is, antibiotic is a word with a broader meaning than polymyxin:

polymyxin: any of several toxic antibiotics obtained from a particular soil bacterium
antibiotic: a chemical substance derivable from a mold or bacterium that can kill microorganisms and cure bacterial infections

Other hypernyms of polymyxin include antibiotic drug.

polymyxin (noun)	antibiotic (noun)
any of several toxic antibiotics obtained from a particular soil bacterium	a chemical substance derivable from a mold or bacterium that can kill microorganisms and cure bacterial infections

polymyxin (adjective)	antibiotic (adjective)
	of or relating to antibiotic drugs