griseofulvin vs penicillin

griseofulvin and penicillin both are nouns.

Word	Noun	Adjective	Verb	Adverb
griseofulvin	Yes	No	No	No
penicillin	Yes	No	No	No

As nouns, penicillin is a hypernym of griseofulvin; that is, penicillin is a word with a broader meaning than griseofulvin:

griseofulvin: a kind of penicillin (a fungicidal antibiotic with the trade name Fulvicin) produced by molds of the genus Penicillium
penicillin: any of various antibiotics obtained from Penicillium molds (or produced synthetically) and used in the treatment of various infections and diseases

Other hypernyms of griseofulvin include antifungal, antifungal agent, antimycotic, antimycotic agent, fungicide.

griseofulvin (noun)	penicillin (noun)
a kind of penicillin (a fungicidal antibiotic with the trade name Fulvicin) produced by molds of the genus Penicillium	any of various antibiotics obtained from Penicillium molds (or produced synthetically) and used in the treatment of various infections and diseases