re·dun·dan·cy 
(rĭ-dŭndən-sē)
(rĭ-dŭndən-sē)n. pl. re·dun·dan·cies
1. The state of being redundant.
2. Something redundant or excessive; a superfluity.
3. Repetition of linguistic information inherent in the structure of a language, as singularity in the sentence It works.
4. Excessive wordiness or repetition in expression.
5. Chiefly British
a. The state or fact of being unemployed because work is no longer offered or considered necessary.
b. A dismissal of an employee from work for being no longer necessary; a layoff.
6. Electronics Duplication or repetition of elements in electronic equipment to provide alternative functional channels in case of failure.
7. Repetition of parts or all of a message to circumvent transmission errors.
8. Genetics See degeneracy.
Usage Note: The usages that critics have condemned as redundancies fall into several classes. Some expressions, such as old adage, mental telepathy, and VAT tax have become fixed expressions and seem harmless enough. In some cases, such as consensus of opinion and hollow tube, the use of what is regarded as an unnecessary modifier or qualifier can sometimes be justified on the grounds that it in fact makes a semantic contribution. Thus a hollow tube can be distinguished from one that has been blocked up with deposits, and a consensus of opinion can be distinguished from a consensus of judgments or practices. Some locutions, such as close proximity, have been so well established that criticizing them may seem petty.