a single piece of information, as a fact, statistic, or code; an item of data.

Philosophy .

any fact assumed to be a matter of direct observation.

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

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

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

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.