adjective Thousand-year-old; also thousands of years old.
adjective Occurring every thousand years.
adjective Occurring at, or relating to, the beginning or end of a millennium.
adjective Referring to the thousandth anniversary of an event or happening.
a millennial fair
adjective Often capitalized: of or relating to, or characteristic of, people born in the last two decades of the 20th century from around the early 1980s to the mid 1990s (with 1996 births cited as the last Millennial year), and who reached adulthood early in the third millennium C.E.
the millennial generation
adjective Synonym of millenarian (“pertaining to the belief in an impending period of one thousand years of peace and righteousness associated with the Second Coming of Christ and his reign on earth”).
the millennial judgment
noun Often capitalized: a person from the generation born in the last two decades of the 20th century, from around the early 1980s to the mid-1990s and who reached adulthood early in the third millennium C.E., characterized by their familiarity with computer technology and poorer financial prospects than their parents.
noun A thousandth anniversary; also, a celebration of such an anniversary.