thirteen
Americannoun
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thirteens
plural
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a cardinal number, 10 plus 3.
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a symbol for this number, as 13 or XIII.
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a set of this many persons or things.
adjective
noun
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the cardinal number that is the sum of ten and three and is a prime number See also number
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a numeral, 13, XIII, etc, representing this number
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the amount or quantity that is three more than ten; baker's dozen
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something represented by, representing, or consisting of 13 units
determiner
Usage
Spelling tips for 13 The word thirteen (13) is hard to spell because it doesn’t simply combine the spelling of the base number (three) with the suffix -teen, as is done in other easy-to-remember spellings like fourteen and sixteen. How to spell thirteen: 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 thirteen.
Other Word Forms
Noun Inflected Forms
Etymology
Origin of thirteen
before 900; late Middle English thirttene, variant of Middle English thrittene, Old English thrēotēne; cognate with Dutch dertien, German dreizehn, Old Norse threttān. See three, -teen
Example Sentences
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
See Examples For:
The Higgs bosons themselves are produced when protons traveling at 99.99% the speed of light collide at energies reaching thirteen trillion electron volts.
From Science Daily ● Sep. 20, 2026
The National Football League season is back in full swing, with thirteen games on tap for the first NFL Sunday.
From Barron's ● Sep. 12, 2026
“He had been president only thirteen days—and now he faced the prospect that to end the war and save American lives, he might have to obliterate Japan’s cities,” Mr. Scott writes.
From The Wall Street Journal ● Jul. 31, 2026
We just got new numbers, and it’s down to one in thirteen, an all-time low.
From Salon ● Mar. 26, 2025
At thirteen he was a musical prodigy and a rascal and the pride of my life.
From "The Hiding Place" by Corrie ten Boom
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Six seeds are 86-50 against the elevens, fives are 89-47 against twelves, and once you get to fours vs. thirteens, you're in never gonna happen territory.
From Golf Digest ● Mar. 18, 2019
I do not know, he adds, what the occult almanac makers predict, but out of curiosity I have looked back at some other thirteens.
From The Guardian ● Jan. 1, 2013
Whenever I have been wrecked, we had sailed as cheerily as you please—no thirteens, no Fridays, no dead men in the hold.
From Man Overboard! by F. Marion (Francis Marion) Crawford
Come in and bear a hand, and I’ll give you diet and lodging and a few thirteens when you earn them.”
From The Irish Fairy Book by Various
In this case the sum of the numbers 1, 11, 6, 9, 4, 7, 9, 6, is 53; casting out the thirteens the remainder is 1, the last of the series.
Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023
Idioms from The American Heritage® Idioms Dictionary copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.