nonagenarian

Yes but for some reason they're mostly used for those on the older end of the spectrum. The only one I ever really hear used is "octogenarian." Here is a list of all the others: [https://www.britannica.com/dictionary/eb/qa/Age-by-Decade](https://www.britannica.com/dictionary/eb/qa/Age-by-Decade)

100 is centenarian. Octogenarian is 80. They’re derived from Latin. 20 would probably be something like viginarian I think? From viginti. 60 should be hexagenarian. Septuagenarian is for 70. Edit: Apparently sexagenarian is more common for 60. 20s is vicenarian. Tricenarian is 30s. I found a list: https://www.britannica.com/dictionary/eb/qa/Age-by-Decade

Ok, here is the practical answer. Someone in their 20s: twenty-something. Someone in their 30s: thirty-something. You might possibly say the same for 40s and 50s or you might say “someone in their 40s” or more likely just “a middle aged person.” 65 divides “seniors.” So that is a bit more vague. Folks in their 60s could be seen as late middle age or seniors or just someone in their 60s. People do occasionally use those fancy words starting with age 70, but more often not.

Yes. Octogenarian is used. Beyond that, I can’t think of any I hear.

There are, but being any age less than 80 is unremarkable. There isn’t much reason to use them. My dad is a nonagenarian, which is worthy of note just because, but he’s also one of four living nonagenarians in his family (second youngest). That word comes up fairly often. But, like, when they were all in their fifties—no one cared, you know?,

i have never heard of this & i'm a native english speaker, but it's interesting! *maybe* i've heard of a "centenarian" but that's about it...

just learned about genarians, some are really hard to pronounce but I think I got the hang of it

Using a fancy word confers a certain level of respect or decorum to the concept. Being twenty years old isn't really remarkable, so while a corresponding word might exist, it's also sort of nonsensical. It doesn't suit what's being talked about. Being 80 or 100 makes you notably old. At that point, your age is something of an accomplishment all on its own. So, a fancy word makes sense. If you want to talk about someone or some people between the ages of 20 and 29, you would likely use either "in their twenties" or "twenty-something." For example, "Jack, Jill, and John are in their twenties." Or, "I spoke to a lovely, blond twenty-something last night." Keep in mind that "twenty-something" is very casual, so it can easily shift to sounding dismissive or rude. The same principle applies to 30, 40, 50, and 60. After 40 or 50, you might start hearing the phrase "over the hill," which is a metaphor/idiom for being in the second half of your life. It's generally used jokingly. If you used it with a stranger, it would likely be perceived as an insult.

It’s Latin, so you could easily guess - cinquegenarian, hexagenarian etc —edit:— quinqagenarian instead, but it wasn’t a bad guess, eh!😂

As others have said, English does have similar words for people in their 20s, 30s, 40s, and onward. But it's more common to use twentysomething, thirtysomething, fortysomething, etc.

Someone in their 70s is a septuagenarian, in their 80s, they're an octagenarian, and at 100+, they're a centenarian. I don't think there are special words for other decades of life.

Octogenarian, septuagenarian and centenarian are all sort of common words in one specific context: traditional journalism. The legacy media is kind of a self-contained linguistic ecosystem that has its own discourse style. Let's say someone wants to write an article on the aging Japanese population. By now, that's a genre of article that's been written over and over for two decades or more. Anyone writing the latest version based on new birthrate stats will probably duplicate much of the language of previous articles, including words like nonagenarian. And yet virtually no one would never use these words in everyday speech, even if specifically chatting about the demographics of a place. Even if chatting about the very same article.

Teen (13–19), twentysomething, thirtysomething, fortysomething, fiftysomething, sexagenarian, septuagenarian, octogenarian, nonogenarian and centenarian (any age in the triple digits).