• synonyms


[ thur-teen ]
/ ˈθɜrˈtin /


a cardinal number, 10 plus 3.
a symbol for this number, as 13 or XIII.
a set of this many persons or things.


amounting to 13 in number.


Why Is Friday The 13th Unlucky?Can you honestly say that you've never felt a slight pang of concern when waking up on the morning of Friday the 13th? You're not alone.

Nearby words

thirlage, thirlmere, thirst, thirst trap, thirsty, thirteen, thirteen colonies, thirteen-lined ground squirrel, thirteenth, thirteenth amendment, thirteenth chord

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 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for thirteen

British Dictionary definitions for thirteen


/ (ˈθɜːˈtiːn) /


the cardinal number that is the sum of ten and three and is a prime numberSee also number (def. 1)
a numeral, 13, XIII, etc, representing this number
the amount or quantity that is three more than ten; baker's dozen
something represented by, representing, or consisting of 13 units


  1. amounting to thirteenthirteen buses
  2. (as pronoun)thirteen of them fell

Word Origin for thirteen

Old English threotēne; see three, -teen
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

Word Origin and History for thirteen



early 15c., metathesis of Old English þreotene (Mercian), þreotiene (West Saxon), from þreo "three" (see three) + -tene (see -teen). Cf. Old Frisian thretten, Dutch dertien, German dreizehn.

Not an unlucky number in medieval England, but associated rather with the customary "extra item" (e.g. baker's dozen). Superstitions began with association with the Last Supper, and the unluckiness of 13 sitting down together to dine (attested from 1690s). Most of the modern superstitions (buildings with floor "12-A," etc.) have developed since 1890.

Online Etymology Dictionary, © 2010 Douglas Harper