next after the twelfth; being the ordinal number for 13.
being one of 13 equal parts.


a thirteenth part, especially of one (1/13).
the thirteenth member of a series.

Origin of thirteenth

before 900; thirteen + -th2; replacing Middle English thrittenthe (see three, tenth), Old English thryttēotha (see tithe) Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for thirteenth

Contemporary Examples of thirteenth

Historical Examples of thirteenth

British Dictionary definitions for thirteenth



(usually prenominal)
  1. coming after the twelfth in numbering or counting order, position, time, etc; being the ordinal number of thirteen: often written 13th
  2. (as noun)Friday the thirteenth


  1. one of 13 equal or nearly equal parts of something
  2. (as modifier)a thirteenth part
the fraction equal to one divided by 13 (1/13)
  1. an interval of one octave plus a sixthSee also interval (def. 5)
  2. short for thirteenth chord
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 thirteenth

early 14c., þriteenþe, from thirteen + -th (1), replacing forms from Old English þteoteoða. Cf. Old Norse þrettande, Danish trettende, Swedish trettonde, Old Frisian threttinde, Dutch dertiende, Old High German dritto-zehanto, German dreizehnte.

Online Etymology Dictionary, © 2010 Douglas Harper