Neanderthal

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A species of extinct hominins (Homo neanderthalensis) that lived throughout most of Europe and western and central Asia during the late Pleistocene Epoch until about 30,000 years ago. Members of this species had a large skull and stocky build and are associated with Middle Paleolithic tools.
• noun An individual belonging to this species.
• noun Slang A crude, boorish, or slow-witted person.
• adjective Of, having to do with, or resembling Neanderthals.
• adjective Slang Crude, boorish, or slow-witted.

from the GNU version of the Collaborative International Dictionary of English.

• proper noun (Anthropol.) A neanderthal human being; a member of the race Homo sapiens neanderthalensis.
• proper noun One resembling a neanderthal human; a troglodyte; a cave man.
• proper noun A person of primitive, unenlightened or uneducated opinions or attitudes; one with a regressive social or political outlook; -- used disparagingly.
• adjective (Anthropol.) Of, pertaining to, or named from, the Neanderthal, a valley in the Rhine Province, in which were found parts of a skeleton of an early type of man. The skull is characterized by extreme dolichocephaly, flat, retreating forehead, with closed frontal sutures, and enormous superciliary ridges. The cranial capacity is estimated at about 1,220 cubic centimeters, being about midway between that of the Pithecanthropus and modern man.
• adjective Similar to or reminiscent of a neanderthal human; troglodytic; primitive and uncultured.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• adjective Of or pertaining to Homines neanderthalenses.
• adjective Old-fashioned, opposed to change (in allusion to Homo neanderthalensis).
• adjective Of or pertaining to the Neander Valley in Germany.
• noun A specimen of the now extinct species Homo neanderthalensis.
• noun pejorative A primitive person.