what does a datum define
Wiktionary (0.00 / 0 votes) Rate this definition: datum (Noun) plural: data A measurement of something on a scale understood by both the recorder (a person or device) and the reader (another person or device). The scale is arbitrarily defined, such as from 1 to 10 by ones, 1 to 100 by 0.1, or simply true or false, on or off, yes, no, or maybe, etc. datum (Noun) plural: data a fact known from direct observation