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

By the early nineties, Sinegal and Brotman (who had become the chairman) were gaining momentum, as was Sam’s Club—Walmart’s warehouse-club chain. —Molly Fischer, New Yorker, 20 Oct. 2025

Dominique Trenier, [D’Angelo’s former manager], was one of my friends, [and] got in trouble somehow [one day in the nineties]. —Andre Gee, Rolling Stone, 16 Oct. 2025

The boxy Rover parked outside Lowestoft station is particularly evocative for a British child of the eighties and nineties. —Literary Hub, 16 Oct. 2025

Everything froze in time until the ball crashed against the foul pole and kicked back into the playing field, making the stadium sound like the old place across the street sounded in the dynastic nineties. —Ian O'Connor, New York Times, 8 Oct. 2025

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