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Y2K

American  
[wahy-too-key] / ˈwaɪˌtuˈkeɪ /

abbreviation

  1. the year 2000.

  2. Also called Y2K bug.  Also called millennium bug.  Also called Y2K problem,.  a bug that could cause computers or software to misinterpret a year after 1999 as having the first two digits 19 instead of 20, due to the coding of dates using only the last two digits of the four-digit year.


adjective

  1. relating to or characteristic of the late 1990s and early 2000s.

    The outfit merges Y2K aesthetics with contemporary trends.

Y2K British  

noun

  1. another name for the year 2000 ad (esp referring to the millennium bug)

"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

Etymology

Origin of Y2K

First recorded in 1995–2000; Y(ear) + 2 + K symbol for the number 1000

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

The SaaSpocalypse will pass, as Y2K and the XPocalypse passed, because capable people will do the work.

From MarketWatch May 27, 2026

The Game, the rapper famous for Y2K hits such as “Hate It Or Love It” and “How We Do,” misses the era when Drake put out at least an album a year.

From The Wall Street Journal May 13, 2026

In the first two decades since Y2K, by contrast, deaths have averaged around three per term.

From Slate Apr. 24, 2026

The Swedish pop sensation has also been behind a make-up trend focused on maximal, glam "Y2K" looks, and that's something Lauren remembers fondly from 2016.

From BBC Jan. 9, 2026

“But . . . ,” he said again, thinking about the neat stack of monthly bills on the kitchen counter and all the Y2K supplies they could buy with a hundred and fifty dollars.

From "The First State of Being" by Erin Entrada Kelly

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