Neandertal man vs human being

Neandertal man and human being both are nouns.

Word	Noun	Adjective	Verb	Adverb
Neandertal man	Yes	No	No	No
human being	Yes	No	No	No

As nouns, human being is a hypernym of Neandertal man; that is, human being is a word with a broader meaning than Neandertal man:

Neandertal man: extinct robust human of Middle Paleolithic in Europe and western Asia
human being: any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage

Other hypernyms of Neandertal man include homo, human, man.

Neandertal man (noun)	human being (noun)
extinct robust human of Middle Paleolithic in Europe and western Asia	any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage