higgledy-piggledy vs hugger-mugger

higgledy-piggledy is not a noun while hugger-mugger is a noun.

Word	Noun	Adjective	Verb	Adverb
higgledy-piggledy	No	Yes	No	Yes
hugger-mugger	Yes	Yes	No	Yes

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

Other synonyms of higgledy-piggledy include disorderly, jumbled, topsy-turvy.

higgledy-piggledy (noun)	hugger-mugger (noun)
	a state of confusion

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

higgledy-piggledy (adverb)	hugger-mugger (adverb)
in a disordered manner	in secrecy