redundancy

noun

1. (countable, uncountable)The state of being redundant.
2. (countable, uncountable)A superfluity; something redundant or excessive; a needless repetition in language.

   “[…] the fulneſs of the creature is limited, it ariſeth juſt to ſuch a degree and proportion, but Gods fulneſs is infinite, as it hath its Reſplendency, ſo its Redundancy, it knows neither bounds nor bottom.”

3. (countable, uncountable)A duplication of components or circuits to provide survival of the total system in case of failure of single components.

   “2006, Lauren Bean, Richard E. Friedman, Chapter 5: School Safety in the Twenty First Century: Adapting to New Security Challenges Post-9/11, James J. F. Forest (editor), Homeland Security: Protecting America′s Targets, Volume 2: Public Spaces and Social Institutions, page 108, Staff redundancy is needed in the event that a supervisor and key unit supervisors are not present or unable to act in an emergency.”

4. (countable, uncountable)Duplication of parts of a message to guard against transmission errors.
5. (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.

   “1981, New Zealand House of Representatives. Parliamentary Debates, Volume 442, page 4212, Has he received any representation from Air New Zealand management about redundancy proposals for Air New Zealand staff; and, if so, do these proposals include redundancy agreements?”

   “1983, UK House of Commons, Papers by Command, Volume 40, page lvi, The potential savings did not take into account once-and-for-all staff redundancy costs of £16.5 million and unspecified costs involved in increasing stock levels […] .”

   “In Estonia, in addition, the ethnical aspects of staff redundancy programmes have to be taken into account.”

   “As well as fighting against pay freezes (the RMT is about to ballot members of TransPennine Express), the union is seeking agreements with Network Rail and train operators that there will be no compulsory redundancies (it already has this agreement with ScotRail). [...] Whether redundancies come and whether they result in industrial action remains to be seen, but it's clear that the RMT is not prepared to show any flexibility towards rail companies.”

6. (countable, uncountable)surplusage inserted in a pleading which may be rejected by the court without impairing the validity of what remains.