If I say, “It’s supposed to rain the day after tomorrow,” that’s normal. But if I say, “It’s supposed to rain overmorrow,” you would wonder what I meant.
Overmorrow means “the day after tomorrow.” It disappeared from the common language in the early twentieth century. Who decided that? I think overmorrow is a useful word, and it takes the place of four words which seems handy.
I think it would be a good word to bring back. “The Zoom meeting is at 10 a.m. overmorrow.” See, it’s a useful twenty-first-century word. I need to find an influencer to bring this word back. Maybe Grammar Girl could do it. We can all use a forward-thinking word.