assiduous

Etymology

It is borrowed from Latin assiduus (“sitting down to something; busy, constant, incessant”) with the suffix -ous,^{[2][3][4][5][6]} from assideō (“to sit beside, attend to”),^[2][6][7][8] formed from ad- (“to”) and sedeō (“to sit”),^{[6][8][9][10]} from Proto-Indo-European *sed- (“to sit”).^[6][10] Klein notes the Latin change of the vowel ē to ī in the compound verb.^[8] According to the OED, the Latin adjective literally meant "sitting down to", hence "closely applying to";^[2] Etymonline explains it as being constantly occupied at one's work.^[6] The Latin verb is also the source of assess,^[11][4][3] and Merriam-Webster Unabridged refers it to assize.^[7]

Earliest recorded meaning

Constant in application, attentive: Merriam-Webster Unabridged dates the first use to 1538,^[7] Etymonline to the 1530s and Dictionary.com to 1530–40.^[6][12] The OED's first quotation, from before 1552 in Leland's New Year's Gift, describes actions as unremitting and persistent.^[2]

Semantic evolution

The word was first used of actions, and since the 17th century also of people who apply themselves steadily to their work.^[2][3] Johnson (1755) defined it simply as "constant in application", quoting Milton's "my assiduous cries" from Paradise Lost.^[13] In the 18th century it took on a servile shade,^[6] and by 1725 it could mean constantly trying to please, obsequiously attentive, a sense now archaic;^[2][3] the Shorter Oxford quotes Samuel Johnson's remark that "few can be assiduous without servility".^[3] A use of things, meaning constant or regular, is recorded only in Evelyn's Fumifugium (1661).^[2]

Timeline

• 1538 – constant in application, attentive.^[7] Etymonline dates the word to the 1530s.^[6]
• before 1552 – of actions, unremitting, persistent.^[2][3]
• 1660 – of people, persevering, unwearyingly diligent.^[2] The Shorter Oxford dates this sense to the early 17th century.^[3]
• 1661 – of things, constant, regular (obsolete).^[2]
• 1725 – constantly trying to please, obsequiously attentive (now archaic).^[2][3]

Meanings

Adjective

1. Showing steady, careful attention and persistent effort; diligent and hard-working: an assiduous keeper of the parish records.^[5][7][2]
2. Of work or an action: carried on with persistence and care; unremitting: months of assiduous restoration.^[5][2][3]
3. (archaic) Eager to please; obsequiously attentive.^[2][3][7]

Word family

• assiduously
• assiduousness
• assiduity
• unassiduous

Related words

• assess
• assize
• sedentary
• sit

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 Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f g h i j Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
4. ^ a b Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
5. ^ a b c Collins English Dictionary (2023), Glasgow: HarperCollins
6. ^ a b c d e f g h Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
7. ^ a b c d e f Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
8. ^ a b c Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ Skeat, Walter W. (1911), A Concise Etymological Dictionary of the English Language, new ed., Oxford: Clarendon Press
10. ^ a b The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
11. ^ Hoad, T. F., ed. (1986), The Concise Oxford Dictionary of English Etymology, Oxford: Clarendon Press
12. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
13. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.