redundancy

Etymology

It is borrowed from Latin redundantia (“an overflowing, excess”),^[2][3][4][5] a derivative of redundāns, the present participle of redundō (“to overflow”).^[3][4] The OED and Etymonline also allow that it was formed in English from redundant and the suffix -ancy.^[2][6] The Latin verb is formed from re- (“again”) and undō (“to rise in waves”), from unda (“a wave”), which Etymonline traces to Proto-Indo-European *wed- (“water; wet”).^[6] The OED compares Spanish redundancia (16th century), Portuguese redundância (1589) and Italian ridondanza (before 1459), and the earlier English noun redundance, recorded from 1572.^[2]

Earliest recorded meaning

The state of being superfluous, more than is needed: 1601, in John Deacon and John Walker's Summarie Answere to Darel.^[2][4] Etymonline dates the word to about 1600, and Dictionary.com to 1595–1605.^[6][3]

Semantic evolution

In the 17th century the word could also name the surplus itself, a sense recorded from 1612 to 1832,^[2] or a single redundant thing or part, from 1631.^[2][6] Johnson (1755) defined it as "superfluity; superabundance".^[7] Technical senses followed in the 19th and 20th centuries: in engineering, the presence in a framework of more members than are needed to make it rigid (1884), and later the deliberate duplication of parts so that a system keeps working when one fails (1960);^[2] in information theory, the use of more elements than the minimum needed to carry a message (1947), which in linguistics became the features of a language that allow it to be understood when some elements are lost (1948);^[2] and in genetics, the property of the genetic code by which more than one triplet codes for the same amino acid (1964).^[2] The sense most familiar in Britain, the loss of a job because the post is no longer needed, is recorded from 1931 in the Economist, chiefly in British use,^[2][6] and since 1936 a redundancy could be an individual case of such a dismissal, mostly in the plural.^[2] It is common in phrases such as redundancy payment.^[8]

Timeline

• 1601 – superfluity, the state of being more than is needed.^[2][4]
• 1612 – the surplus itself (obsolete by 1832).^[2]
• 1631 – a redundant thing or part.^[2][6]
• 1884 – engineering: more members in a framework than are needed for rigidity.^[2]
• 1931 – chiefly British: the state of being surplus to an organization's staffing needs, and so losing one's job.^[2][6]
• 1936 – an individual case of such job loss.^[2]
• 1947 – information theory: more elements than are needed to convey a message.^[2]
• 1948 – linguistics: features that allow a message to be understood despite losses.^[2]
• 1960 – the deliberate duplication of parts in a system as a safeguard.^[2]
• 1964 – genetics: the coding of one amino acid by several triplets.^[2]

Meanings

Noun

1. The state of being superfluous or unnecessary; something that is superfluous: The editor cut every redundancy from the report.^[4][8][2]
2. An excessive supply; profusion, overabundance.^[4][8]
3. Chiefly British: the loss of a job because the employer no longer needs the worker; a case of this: The factory closure led to two hundred redundancies.^[8][2]
4. The duplication of parts in a machine or system so that it keeps working when one of them fails.^[8][2]
5. The repetition of information, or the inclusion of extra information, in a message so that errors in transmission can be detected or overcome; in linguistics, the features of a language that allow it to be understood when parts are lost.^[8][2]

Related words

• redundant
• redundance

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
4. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
6. ^ a b c d e f g Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
8. ^ a b c d e f Collins English Dictionary (2023), Glasgow: HarperCollins