geitenmelker.

Compound of geit (“goat”) + -en- + melken (“to milk”) + -er, a calque of Latin caprimulgus meaning the same, which in turn represents a partial calque of Ancient Greek αἰγοθήλας (aigothḗlas). So named due to the ancient belief that nightjars stole milk from goats, a claim made in Historia animalium by Aristotle in the fourth century BC, repeated in Naturalis Historia by Pliny the Elder in the first century AD and subsequently followed by some medieval authors. In the Low Countries, the claim was notably repeated by Jacob van Maerlant, who in his thirteenth-century Der naturen bloeme refers to Pliny as a source for this claim (and naming the bird agotile, presumably after the Greek).