public lavatory vs john

public lavatory and john both are nouns.

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

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

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

public lavatory (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