ampicillin vs penicillin

ampicillin and penicillin both are nouns.

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

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

ampicillin: semisynthetic penicillin (trade names Principen and Polycillin and SK-Ampicillin)
penicillin: any of various antibiotics obtained from Penicillium molds (or produced synthetically) and used in the treatment of various infections and diseases

ampicillin (noun)	penicillin (noun)
semisynthetic penicillin (trade names Principen and Polycillin and SK-Ampicillin)	any of various antibiotics obtained from Penicillium molds (or produced synthetically) and used in the treatment of various infections and diseases