mil·len·ni·um / məˈlenēəm/ • n. (pl. -len·ni·a / -ˈlenēə/ or -len·ni·ums) a period of a thousand years, esp. when calculated from the traditional date of the birth of Jesus Christ. ∎  an anniversary of a thousand years: the millennium of the Russian Orthodox Church. ∎  (the millennium) the point at which one period of a thousand years ends and another begins. ∎  (the millennium) Christian Theol. the prophesied thousand-year reign of Christ at the end of the age (Rev. 20:1–5). ∎  (the millennium) fig. a utopian period of good government, great happiness, and prosperity.DERIVATIVES: mil·len·ni·al / -ēəl/ adj.

millennium a period of a thousand years, especially when calculated from the traditional date of the birth of Christ. In the Christian Church, the term is also used for the period of one thousand years during which (according to one interpretation of Revelation 20:1–5), Christ will reign in person on earth.

Recorded from the mid 17th century, the word is modern Latin, from mille ‘thousand’, on the pattern of biennium.
millennium bug informal name for a predicted problem with some computers arising from an inability of the software to deal correctly with dates of 1 January 2000 or later, through the misinterpretation of a two-digit number (as 87, 99) used to represent a year without specifying the century concerned.

See also Millennium Dome.

Millennium ★★½ 1989 (PG-13)

The Earth of the future is running out of time The people are sterile and the air is terri ble. To keep the planet viable, Ladd and company must go back in time and yank people off planes that are doomed to crash. Great special effects and well thought out script make this a ball of fun 108m/C VHS, DVD . Kris Kristofferson, Cheryl Ladd, Daniel J. Travanti, Lloyd Bochner, Robert Joy, Brent Carver, Maury Chaykin, David McIlwraith, Al Waxman; D: Michael Anderson Sr.; W: John Varley; C: Rene Ohashi; M: Eric N. Robertson.

millennium Period of 1000 years. The Christian calendar takes the birth of Jesus Christ as year 0. Millenarianism holds that Christ will return to Earth to reign for 1000 years.

millennium period of 1000 years, spec. that during which Christ will reign on earth (Rev. 20: 1–5). XVII. — modL., f. L. mille thousand, after biennium (see BIENNIAL).
So millenarian pert. to (sb. one who believes in) the millennium. XVII. f. late L. millenarius, f. millēnī, distributive of mille; see -ARIAN; whence also millenary XVI.