Watchmaking and precision mechanics

The entry l’impermeabilità is built on the adjective impermeabile, and that adjective leads a second life that English cannot copy. Left on its own with an article in front of it, l’impermeabile is a raincoat, the garment on the peg by the door. Italian turns adjectives into nouns far more readily than we do: the quality becomes a thing, and the thing keeps the adjective’s form, which is why un impermeabile leggero is a light mac and not a light property. English has to change word altogether, because « impermeable » belongs to rock and to membranes, and nobody calls a coat « impermeable » or a watch either. That is the second half of the lesson. On a case back the trade word is « water-resistant », never « waterproof », because the figure stamped there comes from a laboratory press and says nothing about a swimming pool. Italian keeps the one word for the coat, the membrane and the watch, and lets the number carry the difference. So l’impermeabilità in this list is a tested property with a depth attached, not a promise.