next after the thirty-ninth; being the ordinal number for 40.
being one of 40 equal parts.


a fortieth part, especially of one (1/40).
the fortieth member of a series.

Origin of fortieth

before 1100; Middle English fourtithe, Old English fēowertigotha. See forty, -eth2 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fortieth

Contemporary Examples of fortieth

Historical Examples of fortieth

  • At Fortieth Street he looked down to the middle of the block.

    The Spenders

    Harry Leon Wilson

  • Dryden and Scott were not known as authors until each was in his fortieth year.


    Samuel Smiles

  • I told him the Fortieth, and that I had been one of the forlorn hope.

  • His children are pensioned into the third and fourth and fortieth generation.


    Charles Godfrey Leland

  • To be exact he did not go the length of the block between Thirty-ninth and Fortieth.

    From Place to Place

    Irvin S. Cobb

British Dictionary definitions for fortieth



  1. being the ordinal number of forty in numbering or counting order, position, time, etc. Often written: 40th
  2. (as noun)he was the fortieth


  1. one of 40 approximately equal parts of something
  2. (as modifier)a fortieth part
the fraction equal to one divided by 40 (1/40)

Word Origin for fortieth

Old English fēowertigotha
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 fortieth

Old English feowertigoða, from feowertig (see forty) + -th (1). Cf. Old Norse fertugonde, Swedish fyrationde, Danish fyrretyvende.

Online Etymology Dictionary, © 2010 Douglas Harper