drop-dead vs patois

drop-dead is not a noun while patois is a noun.

Word	Noun	Adjective	Verb	Adverb
drop-dead	No	No	No	Yes
patois	Yes	No	No	No

drop-dead (noun)	patois (noun)
	a regional dialect of a language (especially French); usually considered substandard
	a characteristic language of a particular group (as among thieves)

drop-dead (adverb)	patois (adverb)
stunningly or breathtakingly