Pronounced: kor-POCK-ruh-see, noun
Notes: This word has changed in meaning over time
The word nychthemeron means “a full period of a night and a day; 24 hours”
Well, this is a first; I cannot find any information about how long this has been a word; I found it defined with background in multiple places, but nothing on how long it’s been around.
Background / Notes
The word day can refer to just the daylight hours (“our porch light is off during the day”), or most of the daylight hours (“it’s been a long day at work”), or a full 24-hour period (“it will take a day to get the part”). There are the more common uses; there is a sense of “day” that refers to an era – something like “it was the day of the workers”. Because of its uncertainty, our word is definitely 24 hours. From the origin, it meant the night period followed by the day period, but it can be used to refer to any 24-hour continuous period of time. As I noted yesterday, a handy word to know if you want to be technical about a 24-hours period. The word comes from the Greek root nykt or nyx (night) combined with the Greek word hemera (day).