millesimal

noun

mil·les·i·mal mə-ˈle-sə-məl

: the quotient of a unit divided by 1000 : one of 1000 equal parts

millesimal adjective

millesimally

mə-ˈle-sə-mə-lē

adverb

Word History

Etymology

Latin millesimus, adjective, thousandth, from mille

First Known Use

1719, in the meaning defined above

Time Traveler

The first known use of millesimal was in 1719

See more words from the same year

Browse Nearby Words

Milles

millesimal

millet

See all Nearby Words

Cite this Entry

Style

“Millesimal.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/millesimal. Accessed 24 Jul. 2025.

Copy Citation

More from Merriam-Webster

Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.

Can you solve 4 words at once?

Can you solve 4 words at once?

Word of the Day

panacea

Listen to the pronunciation of panacea

See Definitions and Examples »

Get Word of the Day daily email!

Popular in Grammar & Usage

'Affect' vs. 'Effect'

A Guide to Using Semicolons

More Words You Always Have to Look Up

Using Bullet Points ( • )

Words You Always Have to Look Up

Popular in Wordplay

Is 'kryptonite' a real word?

12 Lovely and Unusual Words for the Natural World

Even More Bird Names that Sound Like Insults (and Sometimes Are)

Better Ways to Say 'This Sucks'

8 Words with Fascinating Histories

Popular

'Affect' vs. 'Effect'

Is 'kryptonite' a real word?

12 Lovely and Unusual Words for the Natural World