sleeping partner vs silent partner

sleeping partner and silent partner both are nouns.

Word	Noun	Adjective	Verb	Adverb
sleeping partner	Yes	No	No	No
silent partner	Yes	No	No	No

As nouns, sleeping partner and silent partner are synonyms defined as:

sleeping partner and silent partner: a partner (who usually provides capital) whose association with the enterprise is not public knowledge

sleeping partner (noun)	silent partner (noun)
a partner (who usually provides capital) whose association with the enterprise is not public knowledge	a partner (who usually provides capital) whose association with the enterprise is not public knowledge