plural thirties
1
: a number equal to three times 10 see Table of Numbers
2
thirties plural
: the numbers 30 to 39
specifically
: the years 30 to 39 in a lifetime or century
3
: a sign of completion : end
—usually written 30
wrote thirty on the last page of the story
4
: the second point scored by a side in a game of tennis
thirty
adjective
thirty
pronoun, plural in construction
thir·ti·eth
ˈthər|t|ēə̇th 
ˈthə̄|,
ˈthəi|,
|t|,
|iə̇th
1
: being number 30 in a countable series
the thirtieth day
see Table of Numbers
2
: being one of 30 equal parts into which anything is divisible
a thirtieth share of the money
"
plural -s
1
: number 30 in a countable series
the thirtieth of the month
2
: the quotient of a unit divided by 30 : one of 30 equal parts of anything
one thirtieth of the total
Examples of thirty in a Sentence
Noun (1)
The temperature outside is in the high thirties.
He is in his thirties.
Recent Examples on the Web
Sydney Lake, Fortune, 17 June 2026
Teddy Hoffman was a Starbucks barista and a union leader in his early thirties when Scheiber, a reporter for the Times, met him on a Chicago picket line in late 2022.
—Molly Fischer, New Yorker, 15 June 2026
Both men were in their thirties at the time.
—Christine Pelisek, PEOPLE, 12 June 2026
The group is relatively young, with many of its members in their thirties, and will now look to establish themselves in English football.
—Steve Madeley, New York Times, 11 June 2026
See All Example Sentences for thirty
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Noun
For millennial parents in the Northeast—now in their late thirties and early forties, often with kids, hunting for more space—the numbers have a specific shape.
—Sydney Lake, Fortune, 17 June 2026
Teddy Hoffman was a Starbucks barista and a union leader in his early thirties when Scheiber, a reporter for the Times, met him on a Chicago picket line in late 2022.
—Molly Fischer, New Yorker, 15 June 2026
Both men were in their thirties at the time.
—Christine Pelisek, PEOPLE, 12 June 2026
The group is relatively young, with many of its members in their thirties, and will now look to establish themselves in English football.
—Steve Madeley, New York Times, 11 June 2026
See All Example Sentences for thirty
Cite this Entry
“Thirty.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/thirty. Accessed 20 Jun. 2026.
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