public toilet vs john

public toilet and john both are nouns.

Word	Noun	Adjective	Verb	Adverb
public toilet	Yes	No	No	No
john	Yes	No	No	No

As nouns, john is a hypernym of public toilet; that is, john is a word with a broader meaning than public toilet:

Other hypernyms of public toilet include facility, bathroom, can, lav, lavatory, privy, toilet.

public toilet (noun)	john (noun)
a toilet that is available to the public	a room or building equipped with one or more toilets
	a prostitute's customer