Definition from Wiktionary, the free dictionary
nonagenarian (plural nonagenarians)
- One who is between the age of 90 and 99, inclusive. One who is in his or her tenth decade.
one who is between the ages of 90 and 99
nonagenarian (not comparable)
- Being between the age of 90 and 99, inclusive. In one's tenth decade.
- Of or relating to a nonagenarian.