Y2K Meaning of Y2K in English /wuy"tooh'kay"/ , n.1. the year 2000. 2. Also called Y2K problem . See millennium bug . [ 1995-2000; Y ( ear ) + 2 + K symbol for the number 1000 ] Random House Webster's Unabridged English dictionary. Полный английский словарь Вебстер - Random House . 2012