From Latin nōnāgēnārius (“of the number ninety”) (from nonageni (“ninety each”), from nonaginta (“ninety”), from nona- (akin to novem (“nine”)) + -ginta (akin to viginti (“twenty”)), + -arius) + -an
nonagenarian (plural nonagenarians)
- One who is between the age of 90 and 99, inclusive. One who is in his or her tenth decade.
nonagenarian (not comparable)
- Being between the age of 90 and 99, inclusive. In one's tenth decade.
- Of or relating to a nonagenarian.