bad egg vs vernacular

bad egg and vernacular both are nouns.

Word	Noun	Adjective	Verb	Adverb
bad egg	Yes	No	No	No
vernacular	Yes	Yes	No	No

bad egg (noun)	vernacular (noun)
(old-fashioned slang) a bad person	the everyday speech of the people (as distinguished from literary language)
	a characteristic language of a particular group (as among thieves)

bad egg (adjective)	vernacular (adjective)
	being or characteristic of or appropriate to everyday language