redundancy

noun, plural re·dun·dan·cies.

1. the state of being redundant.
2. superfluous repetition or overlapping, especially of words.
3. a redundant thing, part, or amount; superfluity.
4. the provision of additional or duplicate systems, equipment, etc., that function in case an operating part or system fails, as in a spacecraft.
5. Linguistics.
   1. the inclusion of more information than is necessary for communication, as in those cars, where both words are marked for plurality.
   2. the additional, predictable information so included.
   3. the degree of predictability thereby created.
6. Chiefly British.
   1. the condition or fact of being unemployed; unemployment.
   2. a layoff.

noun plural -cies

1. 1. the state or condition of being redundant or superfluous, esp superfluous in one’s job
   2. (as modifier)a redundancy payment
2. excessive proliferation or profusion, esp of superfluity
3. duplication of components in electronic or mechanical equipment so that operations can continue following failure of a part
4. repetition of information or inclusion of additional information to reduce errors in telecommunication transmissions and computer processing

n.

c.1600; see redundant + -ancy. Sense in employment is from 1931, chiefly British.

Unnecessary repetition in speech or writing. The expression freedom and liberty is redundant.