data

Multiple Entries:
  data    datum  

Concise Oxford English Dictionary © 2008 Oxford University Press:
data /ˈdeɪtə/

▶noun

• 1 facts and statistics used for reference or analysis.

  ■ Philosophy things known or assumed as facts, making the basis of reasoning.

• 2 the quantities, characters, or symbols on which operations are performed by a computer.

– origin C17: from L., pl. of datum.

usage: In Latin, data is the plural of datum and, historically and in specialized scientific fields, it is also treated as a plural in English. In modern non-scientific use, however, it is often treated as a mass noun, similar to a word like information, which cannot normally have a plural and which takes a singular verb. Sentences such as data was collected over a number of years are now widely accepted in standard English.

Concise Oxford English Dictionary © 2008 Oxford University Press:
datum /ˈdeɪtəm/

▶noun (pl. data) See also data.

• 1 a piece of information.

• 2 an assumption or premise from which inferences may be drawn.

• 3 a fixed starting point of a scale or operation.

– origin C18: from L., lit. ‘something given’.