surreptitious vs cloak-and-dagger

surreptitious and cloak-and-dagger both are adjectives.

Word	Noun	Adjective	Verb	Adverb
surreptitious	No	Yes	No	No
cloak-and-dagger	No	Yes	No	No

As adjectives, surreptitious and cloak-and-dagger are synonyms defined as:

surreptitious and cloak-and-dagger: conducted with or marked by hidden aims or methods

Other synonyms of surreptitious include clandestine, hole-and-corner, hugger-mugger, hush-hush, secret, undercover, underground.

surreptitious (adjective)	cloak-and-dagger (adjective)
marked by quiet and caution and secrecy; taking pains to avoid being observed	conducted with or marked by hidden aims or methods
conducted with or marked by hidden aims or methods