lav vs john

lav and john both are nouns.

Word	Noun	Adjective	Verb	Adverb
lav	Yes	No	No	No
john	Yes	No	No	No

As nouns, lav and john are synonyms defined as:

Other synonyms of lav include bathroom, can, lavatory, privy, toilet.

lav (noun)	john (noun)
a room or building equipped with one or more toilets	a room or building equipped with one or more toilets
	a prostitute's customer