thirty

[thur-tee]

noun

plural

thirties 

1. a cardinal number, 10 times 3.

2. a symbol for this number, as 30 or XXX.

3. a set of this many persons or things.

4. Printing, Journalism.,  30-dash.

5. 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

1. amounting to 30 in number.

thirty

/ ˈθɜːtɪ /

noun

1. the cardinal number that is the product of ten and three See also number

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

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

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

5. something representing, represented by, or consisting of 30 units

determiner

1. 1. amounting to thirty

      thirty trees

   2. ( as pronoun )

      thirty are broken

Word History and Origins

Origin of thirty¹

before 900; Middle English thritty, Old English thrītig, equivalent to thrī three + -tig -ty ¹; cognate with Dutch dertig, German dreissig, Old Norse thrjātīu

Word History and Origins

Origin of thirty¹

Old English thrītig; see _three , _-ty ¹

Example Sentences

To future-proof our forests, a 'species for the future' list has been released highlighting thirty trees likely to thrive in a warmer climate.

Read more on BBC

Paul Kouassi, a Yopougon resident in his thirties, said he was more concerned about the lack of job prospects than the election.

Read more on Barron's

The series follows two board-gaming friends in their thirties - Leonard, a ghost writer of children's encyclopaedias, and Hungry Paul, a part-time postal worker who still lives at home.

Read more on BBC

Yet among the book’s chastening details is this: Twenty years ago, there were some 200 full-time lexicographers in the U.S.; now there are “probably closer to thirty.”

Read more on The Wall Street Journal

"We definitely understand this concern," a spokesperson for Wellcome Leap told the BBC, adding that they work with local teams in thirty countries.

Read more on BBC

When To Use

Spelling tips for 30

The word thirty (30) is hard to spell because it doesn’t simply combine the spelling of the base number (three) with the suffix -ty, as is done in other easy-to-remember spellings like sixty and seventy.  How to spell thirty: When three is combined with suffixes, it transforms from three (a cardinal number) to third (an ordinal number).Then, the d is dropped: thirteen (not thirdteen); thirty (not thirdty). Remember: there's no d in thirty.