the state of being redundant.

superfluous repetition or overlapping, esp. of words.

a redundant thing, part, or amount; superfluity.

the provision of additional or duplicate systems, equipment, etc., that function in case an operating part or system fails, as in a spacecraft.

Linguistics .

the inclusion of more information than is necessary for communication, as in those cars, where both words are marked for plurality.

the additional, predictable information so included.

the degree of predictability thereby created.

Chiefly British .

the condition or fact of being unemployed; unemployment.

a layoff.