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

That spunky spirit lingered into the nineties and early two-thousands. —David Remnick, New Yorker, 2 Sep. 2025

The Buttholes began the nineties by accomplishing the unlikely, then the unthinkable. —Pat Blashill, Rolling Stone, 28 Aug. 2025

One of the South's most iconic appetizers fuses with the nineties' obsession with Tex-Mex to create a twist on this beloved party appetizer. —Jenna Sims, Southern Living, 24 Aug. 2025

Photo courtesy of Marvel Studios Originally conceived as supervillains disguising themselves as superheroes in the nineties, the Thunderbolts have gone through many incarnations over the years both in and out of the comics. —Michileen Martin, MSNBC Newsweek, 14 Aug. 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