senile

Etymology

It is borrowed from Latin senīlis (“of or characteristic of old age; old, aged”),^[2][3][4][5] formed from sen-, the stem of senex (“old; old man”), with the suffix -īlis.^[2][4][6] Etymonline takes it through French sénile,^[7] and Barnhart, the Shorter Oxford, Hoad and the Oxford Dictionary of English allow either the French or the Latin word;^{[8][9][10][11]} the OED, revised in 2023, gives only the Latin and compares the French adjective, recorded from 1509 and in medical contexts from the end of the 18th century.^[2] The Latin adjective goes back to Proto-Indo-European *sen- (“old”),^[7][3] and Klein lists among its cognates Ancient Greek ἕνος (hénos, “old”), Lithuanian senas (“old”), Gothic 𐍃𐌹𐌽𐌴𐌹𐌲𐍃 (sineigs, “old”), Old Irish sen (“old”) and Welsh hen (“old”).^[5]

Earliest recorded meaning

Characteristic of, or being of, old age: the OED's first quotations are from two works by F. Sabie of 1595, the Fissher-mans Tale and Flora's Fortune.^[2] Barnhart and Merriam-Webster date the word to 1661, Barnhart in Robert Boyle's writings,^[8][4] and Etymonline to the 1660s.^[7]

Semantic evolution

Johnson (1755) defines it as "belonging to old age; consequent on old age", and his quotation speaks with approval of "a senile maturity of judgment".^[12] In medicine it has been applied to conditions attributed to ageing since 1702, in C. Mather,^[2] and senile dementia is attested by 1851.^[7] The sense "showing the weakness of old age" is first recorded by Barnhart in Thackeray's Vanity Fair (1848),^[8] and by Etymonline by 1882;^[7] the Shorter Oxford puts it in the mid 19th century.^[9] It now refers especially to a loss of mental faculties.^[9][4] It has been said of old and deteriorating things since 1859,^[2] and since 1890, in G. K. Gilbert's Lake Bonneville, of a landscape near the end of a cycle of erosion.^[2] The noun, a person regarded as showing such deterioration, is recorded from 1882,^[2] though Merriam-Webster dates it to 1938.^[4]

Timeline

• 1595 – characteristic of older age; of a person, of older age.^[2]
• 1702 – in medicine, of a condition attributed to ageing.^[2]
• 1848 – showing the weakness of old age.^[8]
• 1851 – senile dementia.^[7]
• 1859 – of a thing, old and deteriorating.^[2]
• 1882 – noun, an old person showing deterioration.^[2]
• 1890 – in physical geography, near the end of a cycle of erosion.^[2]

Meanings

Adjective

1. Of, relating to or typical of old age.^[13][4][9]
2. Weakened by old age, especially having lost mental faculties: Her uncle became senile in his last years and no longer knew the family.^[13][4][9]
3. (medicine) Of a physical or mental condition, occurring in or attributed to old age: senile dementia.^[2][9]
4. Of a thing, old and showing signs of deterioration.^[2][4]
5. (physical geography) Of land forms or rivers, approaching the end of a cycle of erosion.^[13][2][9]

Noun

1. A senile person.^[4][2][9]

Word family

• senilely
• senility
• presenile

Related words

• senate
• senator
• senescence
• senior
• seniority
• senex
• seigneur
• sir
• sire
• surly

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e f g h i Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
6. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
7. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ a b c d Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
9. ^ a b c d e f g h Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
10. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
11. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
12. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
13. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins