Buying a used car

Le disque de frein has a horse hidden inside it. Le frein is the brake of a car, but the word is the Latin frenum arrived almost intact, and frenum was the bit: the metal bar in the animal’s mouth by which a rider holds it back. French kept that root in a small family — freiner, to brake or to slow a thing down; effréné, unbridled, said of a pace or an ambition; réfréner ses envies, to curb one’s appetites. English has none of those and reached elsewhere for the machine: « brake » comes from the Germanic side and is the outsider here. The bridle did cross the Channel, though, and it landed where nobody looks for it, in the verb « to refrain ». That came through Old French from Latin refrenare, to rein back, so « to refrain from asking » is literally to hold yourself in on a bit. The other « refrain », the chorus of a song, is a different word from a different root, and the two only look alike.