Y2K

Etymology
Abbreviated from "year 2000", with "K" standing for 1000, as in the prefix kilo- though capital K as a prefix is often used as x1024. The correct S.I. Prefix is lowercase k.

Noun

 * 1)  millennium bug
 * 1)  millennium bug
 * 1)  millennium bug
 * 1)  millennium bug
 * 1)  millennium bug