[ dey-tuhm, dat-uhm, dah-tuhm ]
See synonyms for datum on Thesaurus.com
noun,plural da·ta [dey-tuh, dat-uh, dah-tuh] /ˈdeɪ tə, ˈdæt ə, ˈdɑ tə/ for 1-3, da·tums for 4, 5.
  1. a single piece of information, as a fact, statistic, or code; an item of data.

  2. Philosophy.

    • any fact assumed to be a matter of direct observation.

    • any proposition assumed or given, from which conclusions may be drawn.

  1. Also called sense datum. Epistemology. the object of knowledge as presented to the mind.: Compare ideatum.

  2. Surveying, Civil Engineering. any level surface, line, or point used as a reference in measuring elevations.

  3. Surveying. a basis for horizontal control surveys, consisting of the longitude and latitude of a certain point, the azimuth of a certain line from this point, and two constants used in defining the terrestrial spheroid.

Origin of datum

First recorded in 1640–50; from Latin: “a thing given,” neuter past participle of dare “to give”

usage note For datum

See data.

Words that may be confused with datum

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

British Dictionary definitions for datum


/ (ˈdeɪtəm, ˈdɑːtəm) /

nounplural -ta (-tə)
  1. a single piece of information; fact

  2. a proposition taken for granted, often in order to construct some theoretical framework upon it; a given: See also sense datum

Origin of datum

C17: from Latin: something given; see data

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012