Neandertal man vs Neanderthal man

Neandertal man and Neanderthal man both are nouns.

Word	Noun	Adjective	Verb	Adverb
Neandertal man	Yes	No	No	No
Neanderthal man	Yes	No	No	No

As nouns, Neandertal man and Neanderthal man are synonyms defined as:

Neandertal man and Neanderthal man: extinct robust human of Middle Paleolithic in Europe and western Asia

Other synonyms of Neandertal man include Homo sapiens neanderthalensis, Neandertal, Neanderthal.

Neandertal man (noun)	Neanderthal man (noun)
extinct robust human of Middle Paleolithic in Europe and western Asia	extinct robust human of Middle Paleolithic in Europe and western Asia