jamais vu vs confusedness

jamais vu and confusedness both are nouns.

Word	Noun	Adjective	Verb	Adverb
jamais vu	Yes	No	No	No
confusedness	Yes	No	No	No

As nouns, confusedness is a hypernym of jamais vu; that is, confusedness is a word with a broader meaning than jamais vu:

jamais vu: the experience of being unfamiliar with a person or situation that is actually very familiar; associated with certain types of epilepsy
confusedness: a mental state characterized by a lack of clear and orderly thought and behavior

Other hypernyms of jamais vu include confusion, disarray, mental confusion, muddiness.

jamais vu (noun)	confusedness (noun)
the experience of being unfamiliar with a person or situation that is actually very familiar; associated with certain types of epilepsy	a mental state characterized by a lack of clear and orderly thought and behavior