Dictionary.com
Thesaurus.com

thirteen

American  
[thur-teen] / ˈθɜrˈtin /

noun

  1. a cardinal number, 10 plus 3.

  2. a symbol for this number, as 13 or XIII.

  3. a set of this many persons or things.


adjective

  1. amounting to 13 in number.

thirteen British  
/ ˈθɜːˈtiːn /

noun

  1. the cardinal number that is the sum of ten and three and is a prime number See also number

  2. a numeral, 13, XIII, etc, representing this number

  3. the amount or quantity that is three more than ten; baker's dozen

  4. something represented by, representing, or consisting of 13 units

"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

determiner

    1. amounting to thirteen

      thirteen buses

    2. ( as pronoun )

      thirteen of them fell

"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

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.

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.

Nevada also joined the group this week, bringing the total number of members to thirteen.

From Los Angeles Times • Sep. 5, 2025

We just got new numbers, and it’s down to one in thirteen, an all-time low.

From Salon • Mar. 26, 2025

In total, 400 police officers were involved in Wednesday's raids, with search warrants issued at thirteen locations across southwest Sydney.

From BBC • Apr. 24, 2024

He started searching for the dead when he was thirteen, but at first he made mistakes.

From Seattle Times • Apr. 4, 2024

And Jewish or not, my thirteen need a break.

From "The Light in Hidden Places" by Sharon Cameron