public convenience vs restroom

public convenience and restroom both are nouns.

Word	Noun	Adjective	Verb	Adverb
public convenience	Yes	No	No	No
restroom	Yes	No	No	No

As nouns, public convenience and restroom are synonyms defined as:

public convenience and restroom: a toilet that is available to the public

Other synonyms of public convenience include comfort station, convenience, public lavatory, public toilet, toilet facility, wash room.

public convenience (noun)	restroom (noun)
a toilet that is available to the public	a toilet that is available to the public