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ascertain

[as-er-teyn]
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verb (used with object)
  1. to find out definitely; learn with certainty or assurance; determine: to ascertain the facts.
  2. Archaic. to make certain, clear, or definitely known.
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Origin of ascertain

1400–50; late Middle English, variant of assertain, acertain < Middle French acertain- (tonic stem of acertener to make certain), equivalent to a- a-5 + certain certain
Related formsas·cer·tain·a·ble, adjectiveas·cer·tain·a·bly, adverbas·cer·tain·er, nounas·cer·tain·ment, nounnon·as·cer·tain·a·ble, adjectivenon·as·cer·tain·a·ble·ness, nounnon·as·cer·tain·a·bly, adverbnon·as·cer·tain·ment, nounpre·as·cer·tain, verb (used with object)pre·as·cer·tain·ment, nounun·as·cer·tain·a·ble, adjectiveun·as·cer·tain·a·bly, adverbun·as·cer·tained, adjectivewell-as·cer·tained, adjective

Synonym study

1. See learn.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for ascertain

Contemporary Examples

Historical Examples

  • All efforts to ascertain your fate proved utterly fruitless.

    Philothea

    Lydia Maria Child

  • We did not ascertain this last fact, however, for some time.

    Ned Myers

    James Fenimore Cooper

  • There was a thick fog, so that it was impossible to ascertain what advantage had been gained.

  • Is it to ascertain this point that you have done me the honour to visit me?

  • They appraised me in their own minds, I saw, and were curious to ascertain what my full value was.

    Little Dorrit

    Charles Dickens


British Dictionary definitions for ascertain

ascertain

verb (tr)
  1. to determine or discover definitely
  2. archaic to make certain
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Derived Formsascertainable, adjectiveascertainably, adverbascertainment, noun

Word Origin

C15: from Old French acertener to make certain
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for ascertain

v.

early 15c., "to inform, to give assurance," from Anglo-French acerteiner, Old French acertener "to assure, certify" (13c.), from a "to" (see ad-) + certain "certain" (see certain). Modern meaning of "find out for sure by experiment or investigation" is first attested 1794. Related: Ascertained; ascertaining.

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Online Etymology Dictionary, © 2010 Douglas Harper