My friend Jerry, a scientist who studiesÂ Lake ErieÂ algae,Â visited the GED class where I tutor to talk about his work. I learned a lot about his research, and I also learned some new words, which I’ve had fun investigating.
Jerry studies diatoms, one-celled plants that have a silica shell called a frustule. I rushed home to check outÂ this word’sÂ etymology and was gratified to find an interesting history. A frustum is a little bite or piece of something, both in English and in Latin, and the -ule ending (Latin frustulum), called a diminutive,Â makes it even littler and cuter.Â The frustules of diatoms areÂ so cute and so little, you need a microscope to see them, and, fortunately, Jerry brought one today to allow us to gaze upon them.
Looking further,Â I discoveredÂ that the root of these words is the verb fruor, which means enjoy, as you would enjoy a little bite of food.
So frustule is related to the words fruit, fructose, and frugal, all derived from the verb fruor. (But not frustrate, from frustra, meaning in vain.)
Then IÂ got curious about diatomÂ and found itÂ means cut in two, becauseÂ diatoms appear to be in two parts. Each one has two thecae, or coverings. So a theca (and I’m going to share this first-declension singular and plural with my students tomorrow — theca and thecae) is a shield or container in Latin, borrowed from the original Greek word. Hence the words bibliotheca or bibliotheque for aÂ library (holder of books) but also — wait for it — cinematheque (holder of movies!)
As my husband John, director of the Cleveland Institute of Art Cinematheque,Â points out, everything in the end comes back to the Cinematheque.
My students are amused to learn that “disco” in Latin means “learn.” The root of discotheque “disco” is Greek for “disc,” i.e., “record.” Discotheques, as you point out, went the way of vinyl discs!
So was a discotheque a holder of discos? What’s a disco? What happened to them? They seem to have disappeared.