da·​tum ˈdā-təm How to pronounce datum (audio) ˈda- How to pronounce datum (audio)
plural data ˈdā-tə How to pronounce datum (audio) ˈda- How to pronounce datum (audio)
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
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 leads a life of its own quite independent of datum, of which it was originally the plural. It occurs in two constructions: as a plural noun (like earnings), taking a plural verb and plural modifiers (such as these, many, a few) but not cardinal numbers, and serving as a referent for plural pronouns (such as they, them); and as an abstract mass noun (like information), taking a singular verb and singular modifiers (such as this, much, little), and being referred to by a singular pronoun (it). Both constructions are standard. The plural construction is more common in print, evidently because the house style of several publishers mandates it.

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 Jonathan Yoder, deputy director of the CDC’s Division of Infectious Disease Readiness and Innovation, said those sites were deemed to have insufficient data because testing hasn’t been in place long enough, or there may not have been enough positive influenza A samples to include. Susanne Rust, Los Angeles Times, 16 May 2024 Legislators in at least seven states considered bills this year, according to data from the Voting Rights Lab. Ashley Lopez, NPR, 16 May 2024 See all Example Sentences for datum 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'datum.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

Dictionary Entries Near datum

Cite this Entry

“Datum.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/datum. Accessed 28 May. 2024.

Kids Definition


da·​tum ˈdāt-əm How to pronounce datum (audio) ˈdat- How to pronounce datum (audio)
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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