Dictionary-enhanced plural guide
What is the Plural of “Millennium”?
Learn the singular and plural noun forms, the rule behind the plural, and examples that show the form in context.
Singular and Plural Form of Millennium
Millennium is the singular noun form. Millennia is the plural form.
Dictionary meaning: A span of 1,000 years. The year 2000 marked the start of a new millennium.
Why is the Plural of Millennium “millennia”?
The Irregular Plural Rule for Millennium
Most English nouns form the plural by adding -s. Example: millennium → millenniums
Plural pattern: irregular.
How to Remember the Plural of Millennium
“millennium” → “millennia” is an irregular plural — there is no rule, so memorise the pair as a whole. Try writing it in 3 sentences today.
A common slip-up: MIL-en-ee-um (first syllable stressed) is incorrect..
Singular vs Plural Examples with Millennium
See millennium and millennia used in real sentences side by side.
Singular: millennium
- We celebrated the millennium on January 1st, 2000. A2
- This event happened over a millennium ago in history. B1
Plural: millennia
- Three millennia have passed since the beginning of the classical period. B2
Common Plural Mistakes with Millennium
Wrong: Two millennium have passed.
Correct: Two millennia have passed.
Plural of millennium is 'millennia', not 'millenniums'.
How to Pronounce Millennium and Millennia
Second syllable stressed: muh-LEN-ee-um. Not mil-LEN-ee-um.
Other Words With the Same Plural Pattern as Millennium
These nouns follow the same irregular rule. Click any word to see its plural page.
A young boy or girl who is not yet an adult.
the two parts at the bottom of your legs that touch the…
A tiny insect that lives around food and moves very fast.
One of two equal parts that make up something complete.
A grown-up male person. A man is an adult male, not a…
The ability to remember things from the past, or the thought you…
One human; a single individual.
Money that a person earns from their job, paid regularly by their…
Origin and Etymology of Millennium
Latin mille (thousand) + annum (year). Literally 'a thousand years'.
Cultural note: The term became prominent in celebrations around the year 2000.
Frequently Asked Questions About the Plural of Millennium
What is the plural of “millennium”?
The plural of “millennium” is “millennia”.
Is “millennia” regular or irregular?
This page classifies it as irregular based on the available plural data.