1. [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.
2. [noun] (plural: data) (philosophy) A fact known from direct observation.
3. [noun] (plural: data) (philosophy) A premise from which conclusions are drawn.
4. [noun] (plural: datums) (cartography) (engineering) A fixed reference point.
5. [noun] An item of factual information derived from measurement or research.
