hugger-mugger vs clandestine

hugger-mugger is a noun but clandestine is not a noun.

Word	Noun	Adjective	Verb	Adverb
hugger-mugger	Yes	Yes	No	Yes
clandestine	No	Yes	No	No

As adjectives, hugger-mugger and clandestine are synonyms defined as:

hugger-mugger and clandestine: conducted with or marked by hidden aims or methods

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

hugger-mugger (noun)	clandestine (noun)
a state of confusion

hugger-mugger (adjective)	clandestine (adjective)
conducted with or marked by hidden aims or methods	conducted with or marked by hidden aims or methods
in utter disorder

hugger-mugger (adverb)	clandestine (adverb)
in secrecy