datum

noun

da·​tum ˈdā-təm How to pronounce datum (audio) ˈda- How to pronounce datum (audio)
ˈdä-
Synonyms of datumnext
1
plural data ˈdā-tə How to pronounce datum (audio) ˈda- How to pronounce datum (audio)
also
ˈdä- How to pronounce datum (audio)
: something given or admitted especially as a basis for reasoning or inference
an important historical datum
This enormous expense—and considerable risk—to pick up a datum or two about geriatrics?Charles Krauthammer
2
plural datums, mathematics : something used as a basis for calculating or measuring
measuring the distance between datum points
… make things more efficient for those of us whose work requires a time datum.Robert Steinbrunn
Is data singular or plural?: Usage Guide

Data comes from the plural of datum, a technical word that refers to a single piece of information. Data continues to function as a plural, especially in technical and formal writing, taking a plural verb and plural modifiers (such as these, many, a few).

The data are compelling.
These data are incorrect.
More data are needed.
As for the data currently available, they are inconclusive.

More commonly, however, data refers to masses or collections of pieces of information, and functions much like the word information itself, taking a singular verb and singular modifiers (such as this, much, little).

The data is compelling.
Little data is available.
That data is flawed.
Is this data accurate?
As for the data we've seen, it's inconclusive.

Both constructions are standard.

Examples of datum in a Sentence

let's begin our discussion of this matter with a datum from actual experience
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
The data examines topics such as decorating for the holidays, baking festive treats, watching Christmas movies and wearing festive clothes. Maggie Menderski, Louisville Courier Journal, 20 Dec. 2025 Researchers who study active shooter incidents say the Brown University shooting is highly unusual, based on decades of data examining similar attacks across the United States. Aaron Parseghian, CBS News, 19 Dec. 2025 The rental car was just one piece of data investigators used to link the Brown shooting suspect to the fatal shooting of the MIT professor. Holmes Lybrand, CNN Money, 19 Dec. 2025 The American Academy of Pediatrics has also said that the current data are lacking. Tom Bartlett, The Atlantic, 19 Dec. 2025 See All Example Sentences for datum

Word History

Etymology

Latin, from neuter of datus

First Known Use

1646, in the meaning defined at sense 1

Time Traveler
The first known use of datum was in 1646

Browse Nearby Words

Cite this Entry

“Datum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/datum. Accessed 21 Dec. 2025.

Kids Definition

datum

noun
da·​tum ˈdāt-əm How to pronounce datum (audio) ˈdat- How to pronounce datum (audio)
ˈdät-
plural data -ə How to pronounce datum (audio) or datums
: something used as a basis for reasoning or arriving at a conclusion or for calculating or measuring

More from Merriam-Webster on datum

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