Neanderthal

The English adjective Neanderthal is pronounced in various ways. (The German Neanderthal, now spelled Neandertal, is a proper noun, the name of a ravine (tal, formerly thal, means 'valley') on the river Düssel, near Dusseldorf. It owes its name as a tribute to the memory of Joachim Neander (1650-1680), a clergyman, and the author of the hymn translated into English as Praise to the Lord, the Almighty, the King of Creation.)

• The RP version most likely to find favour in British Higher Education pronounces it in the German fashion, as far as most British speakers can: 'nee-AND-er-taal' (silent '-h-'), IPA: /ni ˈæn də^r tɑːl/;
• most British academics reject the pronunciations more common in the United States, where the '-th-' has its normal value in English: 'nee-AND-er-th'l' or 'nee-and-ER-th'l', IPA: /ni ˈæn də^r θ^əl or ni æn ˈdə^r θ^əl/.

The word is used in English only (as noun or adjective) to refer to a primitive, or earlier, relative of modern Homo sapiens:

literally it is used in archaeology, biology and palaeology, etc, to mean a very precisely described species, of which the type specimens were discovered in the Neanderthal valley (a mining region);

in common speech, it is used figuratively to link a person or idea, etc, to the notion of Neanderthal or cave-man as stereotyped in much fiction: 'uncivilized', 'sub-human', 'brutish', often with connotations of 'reactionary', 'old-fashioned' or 'ought to be extinct'. (This usage is said by OED to be "humorous and derogatory".)