[mil-yuh nth]


coming last in a series of a million.
being one of a million equal parts.


the millionth member of a series.
a millionth part, especially of one (1/1,000,000).

Origin of millionth

First recorded in 1665–75; million + -th2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for millionth

Contemporary Examples of millionth

  • For the millionth time the picture served to show how mesmerizingly crisp Obama always looks.

    The Daily Beast logo
    The Heat Quotient

    Tina Brown

    October 28, 2008

Historical Examples of millionth

  • If I said I loved you it wouldn't be a millionth part of what I do.

    The Prisoner

    Alice Brown

  • And then I thought for the millionth time what an awful mistake it is to be fastidious.

  • That's three-millionths of a millionth of a ampere-second at one volt.

    The Machine That Saved The World

    William Fitzgerald Jenkins

  • It'll do it all in about a millionth of a second, too—I want to get us all back alive if possible!

    Skylark Three

    Edward Elmer Smith

  • Then for the millionth part of a second their eyes met, and they recognised each other.

    Scarlet and Hyssop

    E. F. Benson

British Dictionary definitions for millionth



  1. one of 1 000 000 approximately equal parts of something
  2. (as modifier)a millionth part
one of 1 000 000 equal divisions of a particular scientific quantityRelated prefix: micro-
the fraction equal to one divided by 1 000 000


(usually prenominal)
  1. being the ordinal number of 1 000 000 in numbering or counting order, etc
  2. (as noun)the millionth to be manufactured
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 millionth

1670s, from million + -th (1).

Online Etymology Dictionary, © 2010 Douglas Harper