ninety

noun

nine·​ty ˈnīn-tē 

plural nineties

1

: a number equal to nine times 10 see Table of Numbers

2

nineties plural : the numbers 90 to 99

specifically : the years 90 to 99 in a lifetime or century

She's in her nineties.

ninetieth

ˈnīn-tē-əth 

adjective or noun

ninety adjective

ninety pronoun, plural in construction

Examples of ninety in a Sentence

During the nineties, he was going to college and working part-time.

Recent Examples on the Web

In its nineties heyday, more than one billion people watched Baywatch each week. —George Nelson For Artnews, Robb Report, 12 Dec. 2024

There are also flashbacks that extend to more recent episodes, including reminiscences of his time as a film-school professor, in the nineties, with his then students Malcolm, Diana, and Emma. —Richard Brody, The New Yorker, 29 Nov. 2024

In the nineties, Colegrove told me, cyclists (or at least bike companies) were having a love affair with beam bikes. —Eben Weiss, Outside Online, 22 Nov. 2024

Yossi Dotan, a Holocaust survivor from the Netherlands in his nineties, didn’t let the attack interrupt his fasting on Yom Kippur, according to a Facebook post by his son Yaron. —Canaan Lidor, Sun Sentinel, 24 Oct. 2024

Word History

Etymology

Middle English ninety, adjective, from Old English nigontig, short for hundnigontig, from hundnigontig, noun, group of 90, from hund-, literally, hundred + nigon nine + -tig group of 10; akin to Old English tīen ten

First Known Use

before the 12th century, in the meaning defined at sense 1

Phrases Containing ninety

• ninety-nine times out of a hundred
• ninety/ninety-nine percent of the time

Kids Definition

ninety

noun

nine·​ty ˈnīnt-ē 

plural nineties

1

: a number equal to nine times 10 see number

2

plural : the numbers 90 to 99 and specifically the years 90 to 99 in a lifetime or century

ninetieth

-ē-əth 

adjective or noun

ninety adjective or pronoun