THE STAIN

One of my favorite kinds of cheese is manchego, which got its name from La Mancha, the region in south-central Spain where it was historically produced (that might also be familiar to some of you as the place where Don Quixote de la Mancha came from in the famous novel by Miguel de Cervantes). That name literally means "the stain" or "patch" in Spanish, but the reason for this connection is highly uncertain and a lot of etymologists think that it's actually not connected. The proposed explanation for this is that it comes from Arabic al-mansha, meaning "birthplace", and that was folk-etymologized to the modern name.  After being borrowed into the English language in 1905, literary usage of manchego rose sharply until a peak in 2014. It's mostly stablized now, making up about 0.0000017% of all English words.