thirty

[ thur-tee ]

/ ˈθɜr ti /

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noun, plural thir·ties.

a cardinal number, 10 times 3.

a symbol for this number, as 30 or XXX.

a set of this many persons or things.

Printing, Journalism. 30-dash.

thirties, the numbers, years, degrees, or the like, from 30 through 39, as in referring to numbered streets, indicating the years of a lifetime or of a century, or referring to degrees of temperature: He works in the East Thirties. She must be in her thirties. The temperature was in the thirties yesterday.

adjective

amounting to 30 in number.

QUIZ

THINGAMABOB OR THINGUMMY: CAN YOU DISTINGUISH BETWEEN THE US AND UK TERMS IN THIS QUIZ?

Do you know the difference between everyday US and UK terminology? Test yourself with this quiz on words that differ across the Atlantic.

Question 1 of 7

In the UK, COTTON CANDY is more commonly known as…

candystring

candyfloss

candypuff

TAKE THE QUIZ TO FIND OUT

Origin of thirty

before 900; Middle English thritty,Old English thrītig, equivalent to thrīthree + -tig-ty¹; cognate with Dutch dertig,German dreissig,Old Norse thrjātīu

Words nearby thirty

thirteen-lined ground squirrel, thirteenth, Thirteenth Amendment, thirteenth chord, thirtieth, thirty, Thirty days hath September, thirty-eight, thirty-eighth, thirty-fifth, thirty-first

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use thirty in a sentence

Participants fared better on nearly all measures of well-being and performance when they had some kind of movement baked into their day, whether it was a single thirty-minute walk or six five-minute walks.
How Exercise Makes You Better at Life|wtaylor|October 17, 2021|Outside Online
The area is basically an enormous, soaking wet sponge, and it rained continuously throughout the trip, with temperatures ranging between the mid-twenties and high-thirties.
A Sleeping Bag Designed to Get Wet|wsiler|August 25, 2021|Outside Online
Thirty-six percent were in favor and 38 percent were opposed.
How the PC Police Threaten Free Speech|Nick Gillespie|January 9, 2015|DAILY BEAST
Thomas Sadoski should be the frontrunner to play every smarmy privileged thirty-something from now on.
'The Newsroom' Ended As It Began: Weird, Controversial, and Noble|Kevin Fallon|December 15, 2014|DAILY BEAST

I'm to be at his Universal bungalow at twelve-thirty for lunch, to meet him for the first time, going to see a man about a job.
Alfred Hitchcock’s Fade to Black: The Great Director’s Final Days|David Freeman|December 13, 2014|DAILY BEAST
By two-thirty on the first afternoon at his house, I long for a cup of coffee but feel awkward about asking.
Alfred Hitchcock’s Fade to Black: The Great Director’s Final Days|David Freeman|December 13, 2014|DAILY BEAST
Thirty-seven years later, that destiny remains largely unattained.
The Post-Brown and Garner Question: Who ‘Deserves’ to Die?|Goldie Taylor|December 9, 2014|DAILY BEAST
I presume the twenty-five or thirty miles at this end is unhealthy, even for natives, but it surely need not be so.
Glances at Europe|Horace Greeley
Within the past thirty years civilization has rapidly taken possession of this lovely region.
Among the Sioux|R. J. Creswell
I doubt that thirty persons per day are carried into or brought out of it by all public conveyances whatever.
Glances at Europe|Horace Greeley
She began the study of drawing at the age of thirty, and her first attempt in oils was made seven years later.
Women in the fine arts, from the Seventh Century B.C. to the Twentieth Century A.D.|Clara Erskine Clement
The amount of the taxed costs is one hundred and thirty-three, six, four, Mr. Perker.
The Posthumous Papers of the Pickwick Club, v. 2(of 2)|Charles Dickens

British Dictionary definitions for thirty

thirty

/ (ˈθɜːtɪ) /

noun plural -ties

the cardinal number that is the product of ten and threeSee also number (def. 1)

a numeral, 30, XXX, etc, representing this number

(plural) the numbers 30–39, esp the 30th to the 39th year of a person's life or of a century

the amount or quantity that is three times as big as ten

something representing, represented by, or consisting of 30 units

determiner

amounting to thirtythirty trees
(as pronoun)thirty are broken

Word Origin for thirty

Old English thrītig; see three, -ty 1

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012