genarian
n. An elderly person.
Etymology
Examples
2007
I have suspected from the time I was 65ish, or a "sexagenarian" (rooted from my newly coined word "genarian," and that can be "septuagenarian," "octogenarian," etc.) that I was beginning to become transparent. …

Please do not erase me from my space in the world. You and I count equally.

Or do I need a flag to wave so you can see me and not treat me as a transparent genarian?
—Rose M. Campbell, “Senior citizens are not invisible,” St. Petersburg Times, March 31, 2007
2007
I see no problem with nonagenarians having driving tests a tad more frequently. Probably some of the other "genarians" could use more frequent testing, as well. My guess is that they will perform better than those who are on the cellphone or text messaging while driving.
—Russell D. Chapman, “Take away the keys?,” The Dallas Morning News, February 24, 2007
1994 (earliest)
Some people say that you should beware of retirement because it'll drag you down.

But don't tell that to Maurice Browning, 83. According to one of his neighbors in Peace Dale, he's found a sense of mission — by trying to grow an 800-pound pumpkin. …

His garden is an expansive project for an octogenarian, or any kind of genarian.
—Gerry Goldstein, “Maurice Browning thrives and grows, just like his garden,” Providence Journal-Bulletin, September 19, 1994
Notes
He celebrated his sixtieth birthday recently, and laughs off the idea that, as a sexagenarian, he ought to calm down. 'Like the sexy bit. Not so keen on the genarian.'
—Patrick Barclay, “Football: The obsession that drives Bates,” The Observer, December 15, 1991