millennial

adjective

1. of or relating to a millennium or the millennium.
2. worthy or suggestive of the millennium.
3. (often initial capital letter) noting or relating to the generation born in the 1980s or 1990s, especially in the U.S.

noun

4. (often initial capital letter) a person born in the 1980s or 1990s, especially in the U.S.; a member of Generation Y: Millennials are facing a deep economic crisis.

adj.1660s, “pertaining to the millennium,” from stem of millennium + -al (1). Meaning “pertaining to a period of 1,000 years” is from 1807. As a noun from 1896, originally “thousandth anniversary.” From 1992 as a generational name for those born in the mid-1980s and thus coming of age around the year 2000.