millennial

Thousand-year-old; also (by extension, loosely) thousands of years old.

The Kraken sleepeth: faintest sunlights flee / About his shadowy sides: above him swell / Huge sponges of millennial growth and height; […]

Occurring every thousand years.

Occurring at, or relating to, the beginning or end of a millennium.

But I would urge you to resist the temptation to swoon into "Waking Life" as though it were a dizzy millennial throwback to a 60's trip movie.

As for Mr. [Thomas] Pynchon's conjuring of millennial New York, it's a total mishmash.

Referring to the thousandth anniversary of an event or happening.

a millennial fair

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

the millennial generation

He was suffering from a typical millennial problem: Which is the correct emoji to use?

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

Someday, Boomers hope, Millennials will build according to great ideals their parents can only envision, act on vital issues their parents can only ponder.

Meet the Millennials, born in or after 1982—the "Babies on Board" of the early [Ronald] Reagan years, the "Have You Hugged Your Child Today?" sixth graders of the early [Bill] Clinton years, the teens of Columbine, and, this year, the much-touted high school Class of 2000, now invading the nation's campuses.

A thousandth anniversary; also, a celebration of such an anniversary.

The Magyar celebrates the millennial of Hungary, not of Austro-Hungary.

Alternative letter-case form of millennial.

Boomers played cassettes in their cars and popularized FM radio. Thirteeners love their compact disks. Today's electronics industry is abuzz with talk of the new digital technology that awaits Millennial teenagers.

Many people, or at least a handful of very loud people, hate to being dubbed Millennial. They see it as derogatory.