The word derby originally referred to a specific horse race that was held annually in the British town of Epsom, Surrey (coincidentally the place Epsom salt was named after, due it being discovered in a local mineral spring). The competition was established in 1780 by Edward Smith-Stanley, the 12th Earl of Derby, and quickly became the most important race in England. Because of its prominence, the term came to be applied to any kind of sporting contest by the late nineteenth century (especially horse races though), giving us the modern definition of the word. Derby has been a surname since the days of Old English, when it was spelled something like Deoraby or Deorby and could best be translated as "deer village". Historical usage of the word derby had two peaks, first in the early twentieth century and then again in 2017.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.