argot vs rhyming slang

argot and rhyming slang both are nouns.

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

As nouns, rhyming slang is a hyponym of argot; that is, rhyming slang is a word with a more specific, narrower meaning than argot:

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

Other hyponyms of argot include street name.

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