redundancy

(countable, uncountable) The state of being redundant
(countable, uncountable) A superfluity; something redundant or excessive; a needless repetition in language
(countable, uncountable) Duplication of components or circuits to provide survival of the total system in case of failure of single components.
(countable, uncountable) Duplication of parts of a message to guard against transmission errors.
(Australia, New-Zealand, UK, countable, uncountable) The state of being unemployed because one's job is no longer necessary; the dismissal of such an employee; a layoff.
(countable, uncountable) surplusage inserted in a pleading which may be rejected by the court without impairing the validity of what remains.