[thou-zuh ndth, -zuh ntth, -zuh nth]


last in order of a series of a thousand.
being one of a thousand equal parts.


a thousandth part, especially of one (1/1000).
the thousandth member of a series.
Also thousandth's place. (in decimal notation) the position of the third digit to the right of the decimal point.

Origin of thousandth

First recorded in 1545–55; thousand + -th2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for thousandth

Contemporary Examples of thousandth

  • That's because even a thousandth of the power of a human brain is—let's be honest—a bit of a joke.

    The Daily Beast logo
    The Robots Are Coming!

    Justin Green

    May 14, 2013

  • His academic semiotic and philosophical works wield a thousandth of the influence of his bestsellers.

    The Daily Beast logo
    This Week’s Hot Reads: Sept. 10, 2012

    Jimmy So

    September 10, 2012

Historical Examples of thousandth

British Dictionary definitions for thousandth



(usually prenominal)
  1. being the ordinal number of 1000 in numbering or counting order, position, time, etc
  2. (as noun)the thousandth in succession


  1. one of 1000 approximately equal parts of something
  2. (as modifier)a thousandth part
one of 1000 equal divisions of a particular scientific quantitymillivolt Related prefix: milli-
the fraction equal to one divided by 1000 (1/1000)
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 thousandth

1550s, from thousand + -th (1).

Online Etymology Dictionary, © 2010 Douglas Harper