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

Kelly, who came to New York in his twenties, to pursue acting, used to take his boyfriend to the Stonewall in the nineties, for bingo nights hosted by the drag queen Kenny Dash. —Michael Schulman, The New Yorker, 13 Jan. 2025

That’s a reference to a luxury cruise ship ad from the nineties, by the way. —Hazlitt, 13 Nov. 2024

The bar’s iconic nineties movie portraits will be swapped out for photos of Mr. and Mrs. Claus. —Michele Herrmann, Forbes, 20 Dec. 2024

Clint Eastwood is still delivering solid films for grown-ups, well into his nineties. —Brian Tallerico, Vulture, 17 Dec. 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