/non'euh jeuh nair"ee euhn, noh'neuh-/ , adj.
1. of the age of 90 years, or between 90 and 100 years old.
n.
2. a nonagenarian person.
[ 1795-1805; nonagenari ( us ) containing ninety, consisting of ninety ( nonagen ( i ) ninety each + -arius -ARY) + -AN ]