Lubricants and tribology

The twenty-first entry is il metallo di usura, and the last noun in it is one an English reader will misread before reading it right. L’usura is wear: the slow loss of material from a surface that has been rubbed. Le parti soggette a usura are the wearing parts, l’usura del cuscinetto is how far a bearing has gone, and l’additivo antiusura, six entries earlier, is there to slow it down. The word is Latin usura, from usus, the use of a thing — and in Rome it already named the price paid for the use of money as well. English took the word over for that second sense alone. « Usury » is lending at a wicked rate and « a usurer » is the man who does it, while for the first sense English reached for a plain Germanic verb and settled on « wear ». Italian kept the two together, so l’usura in a laboratory report and l’usura in a criminal court are one noun doing two very old jobs.