ascertain

Etymology

It is inherited from Middle English acertainen, also ascertainen and assertainen,^[2][3][4] borrowed from Anglo-Norman acerteiner (“to inform, apprise”),^[5][6][7] from Old French acertener (“to assure, certify”),^[7][6][8] more exactly from its stem acertain-, used where the stem was stressed.^{[9][10][11][12]} The French verb is formed from a- (“to”), from Latin ad-, and certain (“sure”),^[7][6][3] which goes back to Latin certus (“settled, sure”).^[13] The Anglo-Norman verb is recorded from 1292.^[5] In English the word was assimilated to certain, and the present spelling began with assertayne;^[9] Weekley thought it was probably modelled on assure.^[14]

Earliest recorded meaning

To inform, to give assurance: Barnhart finds assertenyng, giving assurance, in 1417, and ascertenen, to inform, in 1425, in the Proceedings of the Privy Council;^[6][15] the Middle English Dictionary quotes the Privy Council in 1427.^[2] The OED's first record is a letter of Queen Margaret of 1450.^[9]

Semantic evolution

The early senses were "subjective": to make a person certain of something, to assure or inform him, a use the OED records until the late 18th century.^[9][10] From the early 16th century the verb was also used of making a thing certain, fixing or establishing it,^[9][4] and Johnson (1755) gave this as its first meaning.^[16] Trench pointed out that when Swift proposed "correcting, improving, and ascertaining the English Tongue" he meant to give the language fixed and certain forms, not to find out what it was.^[17] The modern sense, to find out for certain by investigation, is recorded from 1794,^[9][7] and the OED calls it the only current one;^[9] Weekley derived it from the reflexive use, to ascertain oneself of something,^[14] which the OED records from 1601 to 1731.^[9] The word was pronounced with the stress on the second syllable and the vowel of certain as late as 1650.^[9] An adjective ascertain, certain, is recorded once, in Caxton (1477).^[9]

Timeline

• 1417 – assertenyng, giving assurance.^[6]
• 1427 – acertened, informed, in the Proceedings of the Privy Council.^[2]
• 1450 – to make a person certain; to inform.^[9]
• 1477 – the adjective ascertain, certain, in Caxton.^[9]
• before 1513 – to make a thing certain; to establish it.^[9]
• 1601 – reflexive, to make oneself sure of something (obsolete by 1731).^[9]
• 1794 – to find out for certain by investigation.^[9][7]

Meanings

Verb

1. To find out for certain, by inquiry, experiment or investigation: The inspectors tried to ascertain the cause of the fire.^[4][18][9]
2. (archaic) To make a thing certain; to establish or determine it with certainty.^[4][9]
3. (obsolete, 1450–1789) To make a person sure or confident of something; to assure or inform.^[4][9][10]

Word family

• ascertainable
• ascertainableness
• ascertainably
• ascertainment
• ascertainer
• unascertained
• preascertain

Related words

• certain
• certify
• certitude

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c Kurath, Hans; Kuhn, Sherman M.; Lewis, Robert E., eds. (1952–2001), Middle English Dictionary, Ann Arbor: University of Michigan Press; online edition ed. Frances McSparran et al. (2000–2018)
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 Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b Anglo-Norman Dictionary (AND2), Aberystwyth University, anglo-norman.net (2nd ed., 2005–)
6. ^ a b c d e Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
8. ^ Klein, Ernest. A Comprehensive Etymological Dictionary of the English Language. 2 vols. Amsterdam: Elsevier, 1966–1967.
9. ^ a b c d e f g h i j k l m n o p q r Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
10. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
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. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
14. ^ a b Weekley, Ernest (1921), An Etymological Dictionary of Modern English, London: John Murray
15. ^ Barnhart, Robert K., ed. (1995), The Barnhart Concise Dictionary of Etymology, New York: HarperCollins
16. ^ Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
17. ^ Trench, Richard Chenevix (1859), A Select Glossary of English Words Used Formerly in Senses Different from Their Present, London: John W. Parker
18. ^ Collins English Dictionary (2023), Glasgow: HarperCollins