hiddenness vs concealment

hiddenness and concealment both are nouns.

Word	Noun	Adjective	Verb	Adverb
hiddenness	Yes	No	No	No
concealment	Yes	No	No	No

As nouns, concealment is a hypernym of hiddenness; that is, concealment is a word with a broader meaning than hiddenness:

Other hypernyms of hiddenness include privacy, privateness, secrecy.

hiddenness (noun)	concealment (noun)
the state of being covert and hidden	the activity of keeping something secret
	a covering that serves to conceal or shelter something
	the condition of being concealed or hidden