nonagenarian/ˌnɑnəd͡ʒɪˈnɛriən/EtymologyFrom Latin nōnāgēnārius (“containing ninety”) + -an (suffix forming adjectives and representative nouns), either directly or via French nonagénaire, from nōnāgēnī (“ninety each”) + -ārius (“-ary”), from nōnāginta (“nine tens, ninety”).adjOf or related to ninetysomethings.“"But what’s that got to do with your health and longevity?" the neighbor inquired. "Why," said the nonagenarian, "I've spent most of my life in the open air."”nounSynonym of ninetysomething: a person between 90 and 99 years old.