Polycillin vs penicillin

Polycillin and penicillin both are nouns.

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

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

Polycillin: 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

Polycillin (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