noun, plural fif·ties.

a cardinal number, ten times five.
a symbol for this number, as 50 or L.
a set of this many persons or things.
fifties, the numbers, years, degrees, or the like, from 50 through 59, as in referring to numbered streets, indicating the years of a lifetime or of a century, or degrees of temperature: She lives in the East Fifties. He's in his late fifties. It's going to be in the fifties again today.
Informal. a fifty-dollar bill: He had a fifty and two tens in his wallet.


amounting to 50 in number.

Origin of fifty

before 900; Middle English; Old English fīftig. See five, -ty1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for fifties

Contemporary Examples of fifties

  • Throughout the fifties, in city after city, fluoridation became the subject of fierce debate.

    The Daily Beast logo
    Anti-Fluoriders Are The OG Anti-Vaxxers

    Michael Schulson

    July 27, 2016

  • I struck up a conversation with a man in his fifties or sixties who had a Brooklyn accent.

    The Daily Beast logo
    I Ate Potato Pancakes Til I Plotzed

    Emily Shire

    December 17, 2014

  • PANKISI GORGE, Georgia—The mother of martyrs, a woman in her fifties, is delicately beautiful and visibly in pain.

    The Daily Beast logo
    The Secret Life of an ISIS Warlord

    Will Cathcart, Vazha Tavberidze, Nino Burchuladze

    October 27, 2014

  • An earthquake finally destroyed the town in the Fifties, but it really started to die when the Christian population was deported.

    The Daily Beast logo
    Turkey's Gorgeous Ghost Town

    Nina Strochlic

    July 12, 2014

  • “Oh, they are with us,” said the leader of the group, a man in his fifties, dressed in camouflage, wearing a peaked military cap.

    The Daily Beast logo
    Are East Ukraine's Cops in Moscow's Pocket?

    David Patrikarakos

    April 15, 2014

Historical Examples of fifties

  • I 'll take you two to one in fifties that I act the host here this day twelvemonth.

    Roland Cashel

    Charles James Lever

  • You are swept off by dozens at a time there—by fifties in a cave.

    Love and Lucy

    Maurice Henry Hewlett

  • In villages they can be counted by tens, in towns by fifties.

  • Up to the Christmas of that year he had kept the appearance of a man in his fifties.

    The Genius

    Margaret Horton Potter

  • She must now be somewhere in the fifties—let's see—fifty-three, I think.

    The Ideal

    Stanley Grauman Weinbaum

British Dictionary definitions for fifties


noun plural -ties

the cardinal number that is the product of ten and five
a numeral, 50, L, etc, representing this number
something represented by, representing, or consisting of 50 units


  1. amounting to fiftyfifty people
  2. (as pronoun)fifty should be sufficient

Word Origin for fifty

Old English fīftig
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 fifties

1826 as the years of someone's life between 50 and 59; 1853 as a decade of years in a given century. See fifty.



Old English fiftig, from fif "five" (see five) + -tig "group of ten" (see -ty (1)). Cf. Old Frisian fiftich, Old Norse fimm tigir, Dutch vijftig, Old High German fimfzug, German fünfzig, Gothic fimf tigjus. U.S. colloquial fifty-fifty "in an even division" is from 1913.

Online Etymology Dictionary, © 2010 Douglas Harper