Sleep medicine

The fifteenth entry is la somnolence diurne, and the adjective on the end is a word English owns and almost never says. « Diurnal » is there in the dictionary, built on the same Latin diurnus, of the day, and it has been pushed into two corners. One is zoology, where a diurnal animal is awake while it is light; the other is astronomy, where the diurnal motion is the sky’s apparent turn in twenty-four hours. Nobody uses it in a waiting room. The French word lives in the middle of the language instead: le travail diurne is day work, le rythme diurne is the daily rhythm, la tension diurne is daytime blood pressure, and it pairs with nocturne, which appears twice further down this page, as easily as « day » pairs with « night ». Two things follow. « Diurnal somnolence » reads as though it had been lifted from a paper about lizards; the clinic says « excessive daytime sleepiness ». And English has no everyday adjective for this at all, so it presses the noun « day » into service in front of another noun and leaves it there.