Neanderthal man vs Neandertal man

Neanderthal man and Neandertal man both are nouns.

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

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

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

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

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