noun, plural nine·ties.

a cardinal number, ten times nine.
a symbol for this number, as 90 or XC.
a set of this many persons or things.
nineties, the numbers, years, degrees, or the like, from 90 through 99, as in referring to numbered streets, indicating the years of a lifetime or of a century, or degrees of temperature: His grandmother is in her nineties.


amounting to 90 in number.

Origin of ninety

before 1000; Middle English nineti, Old English nigontig. See nine, -ty1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for ninety

Contemporary Examples of ninety

Historical Examples of ninety

  • Do you mean that you have earned ninety cents to-day, Robert?

    Brave and Bold

    Horatio Alger

  • The marketman handed Robert ninety cents, which he pocketed with satisfaction.

    Brave and Bold

    Horatio Alger

  • Diablo's got ninety to carry, an' he gave the other twenty pounds to-day.


    W. A. Fraser

  • Would not any one think, now, you were an old man of ninety?

  • The wood, therefore, was perhaps eighty or ninety years old.

    The Village Watch-Tower

    (AKA Kate Douglas Riggs) Kate Douglas Wiggin

British Dictionary definitions for ninety


noun plural -ties

the cardinal number that is the product of ten and nineSee also number (def. 1)
a numeral, 90, XC, etc, representing this number
something represented by, representing, or consisting of 90 units


  1. amounting to ninetyninety times out of a hundred
  2. (as pronoun)at least ninety are thought to be missing

Word Origin for ninety

Old English nigontig
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 ninety

Old English nigontig, from nine + -tig "group of ten" (see -ty (1)). Cognate with Old Frisian niontich, Middle Dutch negentich, Dutch negentig, German neunzig.

Online Etymology Dictionary, © 2010 Douglas Harper