a deterioration of mental faculties; senility

Funny word, huh? The definition is probably nothing like what you might expect if you thought it had something to do with “doting,” which means showing too much affection or love. Well, it does have something to do with “doting”—at least the words are connected by a common root—but their definitions seem to have taken different paths in their old age. The word “dotty” is also derived from the same root as “dotage,” which makes a lot more sense to me. Anyway, I figured I should make this my word of the day today because my wife just used it in our (belated) Christmas letter that we probably won’t send for another couple weeks. Maybe we can make it a Saint Knut’s Day letter. That would be very Swedish of us.