rhyming slang vs patois

rhyming slang and patois both are nouns.

Word	Noun	Adjective	Verb	Adverb
rhyming slang	Yes	No	No	No
patois	Yes	No	No	No

As nouns, patois is a hypernym of rhyming slang; that is, patois is a word with a broader meaning than rhyming slang:

rhyming slang: slang that replaces words with rhyming words or expressions and then typically omits the rhyming component
patois: a characteristic language of a particular group (as among thieves)

Other hypernyms of rhyming slang include argot, cant, jargon, lingo, slang, vernacular.

rhyming slang (noun)	patois (noun)
slang that replaces words with rhyming words or expressions and then typically omits the rhyming component	a regional dialect of a language (especially French); usually considered substandard
	a characteristic language of a particular group (as among thieves)