What does millennium mean?
A millennium is a span of one thousand years, or the beginning of such a span. The word is especially common in historical and cultural discussions, where 'the new millennium' commonly means the period since 1 January 2001, although people sometimes describe 2000 as the starting point. The term can also be used metaphorically for a transformative era, as in 'a digital millennium,' though this usage is less formal. Its plural is usually millennia. The word comes from Latin, where mille means 'thousand' and annus means 'year.' Because a calendar millennium is aligned with years ending in 001, the third millennium began in 2001 rather than 2000. Millennium is useful when discussing long historical periods, long-term technological change, and the conventional division of time into thousand-year units.
nounA period of one thousand years. The word can also refer to the beginning of such a period, especially the arrival of a new millennium.
- A period of one thousand years.
- The beginning of a thousand-year period, especially the beginning of a new millennium.
- A period of great technological, social, or cultural change imagined as lasting for a long time.
"The internet has transformed communication during the first decade of the new millennium."
"The cathedral's construction spanned much of the first millennium."
"Scientists debated how the new millennium would reshape medicine."
Millennia is the traditional and most common plural. 'Milleniums' is also accepted in modern English.
"Several millennia of human history are represented in the museum's collection."
The year 1000 was once imagined as the first year of a new millennium, although the modern calendar technically began the third millennium on 1 January 2001.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does millennium come from?
The word comes from Latin millennium, formed from mille, 'thousand,' and annus, 'year.' It entered English in the late Middle English period, initially referring to a thousand-year period, especially in religious and historical contexts. Related Latin formations include millenary, referring to a thousand years, and millenarian, relating to the millennium. English later developed the adjective millennial, which describes something occurring in or associated with a millennium.
Related word forms
How millennium is actually used
The singular form is millennium; the established plural is millennia, while milleniums and millennia are both widely recognized. In expressions such as 'the new millennium,' the term often refers broadly to the era beginning in 2001, despite popular usage sometimes placing its start in 2000.