Watchmaking and precision mechanics

The part that keeps time in a mechanical watch is named after the one thing it never does. Die Unruh is the balance, the small wheel that swings to and fro under its hairspring several times a second, and the word is simply die Unruhe, restlessness, with the final -e worn away in the workshop. German names the part after what it does rather than what it is, and the name is exact: the moment the balance comes to rest, the watch has stopped. The trade builds its compounds on the short form — die Unruhwelle, die Unruhspirale, der Unruhkloben — while everyday German keeps the long form for unease and unrest. Read the rest of this list with that in mind: almost every word in it names something that feeds that restlessness, measures it or keeps it even.