ascertain

[ as-er-teyn ]
See synonyms for: ascertainascertainedascertainingascertainable on Thesaurus.com

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.

Origin of ascertain

1
First recorded in 1400–50; late Middle English, variant of acertain, assertain, from Middle French acertain-, stem of acertener “to make certain”; equivalent to a-5 + certain

Other words from ascertain

  • as·cer·tain·a·ble, adjective
  • as·cer·tain·a·bly, adverb
  • as·cer·tain·er, noun
  • as·cer·tain·ment, noun
  • non·as·cer·tain·a·ble, adjective
  • non·as·cer·tain·a·ble·ness, noun
  • non·as·cer·tain·a·bly, adverb
  • non·as·cer·tain·ment, noun
  • pre·as·cer·tain, verb (used with object)
  • pre·as·cer·tain·ment, noun
  • un·as·cer·tain·a·ble, adjective
  • un·as·cer·tain·a·bly, adverb
  • un·as·cer·tained, adjective
  • well-as·cer·tained, adjective

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2024

How to use ascertain in a sentence

British Dictionary definitions for ascertain

ascertain

/ (ˌæsəˈteɪn) /


verb(tr)
  1. to determine or discover definitely

  2. archaic to make certain

Origin of ascertain

1
C15: from Old French acertener to make certain

Derived forms of ascertain

  • ascertainable, adjective
  • ascertainably, adverb
  • ascertainment, noun

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