The most famous extinct human relative is named after a hymn-writer's love of a valley.
Neanderthal is a German place name, "Neander Valley." It is a gorge of the Düssel River near Düsseldorf, and the first fossil of the group was identified there in 1856. Etymonline records the word in English in 1861 as an adjective.
The valley's name comes from Joachim Neander, a pastor, poet and hymn-writer who loved to walk there in the 1670s. He wrote the hymn known in English as "Praise to the Lord, the Almighty," and he died of tuberculosis at about thirty.
"Neander" was not the name he was born with. His family name was Neumann, "new man," and educated Germans of the time often swapped their surnames for Greek or Latin forms. The Greek version of "new man" gives Neander. Sources disagree on one detail: Etymonline says Joachim made the change, while another Etymonline column says it was his grandfather. They also differ on when the valley took his name, either soon after his death in 1680 or in the early 1800s.
The suffix is German thal, now usually spelled tal after Germany's spelling reform of 1904. English and the species name kept the older th. William King proposed the scientific name Homo neanderthalensis in 1864, and the h must stay in the Latin name under naming rules. Ernst Haeckel suggested Homo stupidus in 1866, but King's name had priority.
The same thal is hidden in the dollar, though by a different valley. The Bohemian town of Joachimsthal minted a coin called the Joachimstaler, shortened to thaler, and that became the dollar. The shared word for "valley" is the only link.
Neanderthal also became an insult, recorded from 1926 for a big, brutish person, though the species itself is now known to have interbred with modern humans.