Meaning of DATUM in English
n. (pl. data: see DATA as main entry). 1 a piece of information. 2 a thing known or granted; an assumption or premiss from which inferences may be drawn (see sense-datum). 3 a fixed starting-point of a scale etc. (datum-line).
[ L, = thing given, neut. past part. of dare give ]
Concise Oxford English dictionary. Краткий оксфордский словарь английского языка. 2012