Etymograph

English

millennial

Millennial comes from Latin mīllennis ‘thousand-year’, and goes back to Proto-Indo-European *h₂et- ‘grass’.

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂et-1‘grass’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂etnós1reconstructed
  3. Proto-Italicc. 1500–700 BCE*atnos1‘year’uncertain
  4. Latinc. 75 BCE–200 CEannus1‘year’
  5. Latinc. 75 BCE–200 CEannīs1
  6. Latinc. 75 BCE–200 CEmīllennis1‘thousand-year’
  7. Late Latinc. 200–600 CEmīllennium2
  8. Englishearliest quotation 1660millennial2

attested reconstructed ? uncertain or disputed deepest recorded ancestor

  1. 1 Wiktionary, Latin millennium
  2. 2 Wiktionary, English millennial
  3. Earliest quotation in Wiktionary’s entry: 1660, Henry More, London: […] J[ames] Flesher: “VVhereas the very Povver of the Civil Magisſtrate and…”.

Lineage

  1. Proto-Indo-Europeanc. 4500–2500 BCE*h₂et-Wiktionary, Latin millennium‘grass’reconstructed
  2. Proto-Indo-Europeanc. 4500–2500 BCE*h₂etnósWiktionary, Latin millenniumreconstructed
  3. Proto-Italicc. 1500–700 BCE*atnosWiktionary, Latin millennium‘year’uncertain
  4. Latinc. 75 BCE–200 CEannusWiktionary, Latin millennium‘year’
  5. Latinc. 75 BCE–200 CEannīsWiktionary, Latin millennium
  6. Latinc. 75 BCE–200 CEmīllennisWiktionary, Latin millennium‘thousand-year’
  7. Late Latinc. 200–600 CEmīllenniumWiktionary, English millennial
  8. Englishearliest quotation 1660millennialWiktionary, English millennial. Earliest quotation in Wiktionary’s entry: 1660, Henry More, London: […] J[ames] Flesher: “VVhereas the very Povver of the Civil Magisſtrate and…”

The story

The adjective is a learned borrowing from Late Latin mīllennium (‘millennium’) + English -al (suffix meaning ‘of or pertaining to’ forming adjectives; and forming nouns). The English word may be analysed as millennium + -al or milli- (prefix meaning ‘thousand’) + -ennial (suffix meaning ‘years’). Adjective sense 5 (‘of or relating to, or characteristic of, people born in the last two decades of the 20th century’) was coined by the American authors William Strauss (1947–2007) and Neil Howe (born 1951) in their book Generations (1991): see the quotations.

Full etymology on Wiktionary

Linked words

through Latin annus ‘year’

annual, ann, annuity, annum, perennial, biennial, 13 more

Today it means

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

Sources

Sources: Wiktionary, “millennial”; the older steps come from the Wiktionary entry for Latin millennium. By Wiktionary contributors, CC BY-SA 4.0, via kaikki.org (dump of Oct 3 2026); text adapted and restructured. Language periods are conventional ranges, not dates for this word. License.

Etymograph / Proto-Indo-European *h₂et- / millennial

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