cloak-and-dagger vs hush-hush

cloak-and-dagger and hush-hush both are adjectives.

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

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

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

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

cloak-and-dagger (adjective)	hush-hush (adjective)
conducted with or marked by hidden aims or methods	conducted with or marked by hidden aims or methods