Gastroenterology

The thirteenth entry is il deficit di lattasi, and the noun in it is a word English owns as well and spends somewhere else entirely. « Deficit » in English belongs first to accounts — a budget deficit, a trade deficit, the shortfall at the bottom of a column — and second to a capacity that has been lost: a neurological deficit, an attention deficit, a hearing deficit. The one thing it is not used for is a substance the body has too little of. There the language insists on « deficiency »: iron deficiency, vitamin D deficiency, and this entry, which is « lactase deficiency » and never a lactase deficit. Italian draws no such line. Il deficit serves for the accounts, il deficit di bilancio, for the lost capacity, il deficit cognitivo, and for the missing enzyme alike, so the sense arrives only with whatever follows the word. Going the other way the rule is short enough to carry about: short in the account or gone from the brain, a deficit; short in the body, a deficiency.