[1] : The Collaborative International Dictionary of English v.0.48

ascertain \as`certain"\, v. t. imp.  p. p. ascertained; p.
   pr.  vb. n. ascertaining. of. acertener; a l. ad +
   certain. see certain.
   1. to render a person certain; to cause to feel certain; to
      make confident; to assure; to apprise. obs.
      1913 webster

            when the blessed virgin was so ascertained. --jer.
                                                  taylor.
      1913 webster

            muncer assured them that the design was approved of
            by heaven, and that the almighty had in a dream
            ascertained him of its effects.       --robertson.
      1913 webster

   2. to make a thing certain to the mind; to free from
      obscurity, doubt, or change; to make sure of; to fix; to
      determine. archaic
      1913 webster

            the divine law . . . ascertaineth the truth.
                                                  --hooker.
      1913 webster

            the very deferring of his execution shall increase
            and ascertain the condemnation.       --jer. taylor.
      1913 webster

            the ministry, in order to ascertain a majority . . .
            persuaded the queen to create twelve new peers.
                                                  --smollett.
      1913 webster

            the mildness and precision of their laws ascertained
            the rule and measure of taxation.     --gibbon.
      1913 webster

   3. to find out or learn for a certainty, by trial,
      examination, or experiment; to get to know; as, to
      ascertain the weight of a commodity, or the purity of a
      metal.
      1913 webster

            he was there only for the purpose of ascertaining
            whether a descent on england was practicable.
                                                  --macaulay.
      1913 webster
see also:
ascertained ascertaining certain 

[2] : WordNet (r) 2.0

ascertain
     v 1: after a calculation, investigation, experiment, survey, or
          study; "find the product of two numbers"; "the physicist
          who found the elusive particle won the nobel prize"
          syn: determine, find, find out
     2: be careful or certain to do something; make certain of
        something; "he verified that the valves were closed"; "see
        that the curtains are closed"; "control the quality of the
        product" syn: see, check, insure, see to it, ensure,
         control, assure
     3: find out, learn, or determine with certainty, usually by
        making an inquiry or other effort; "i want to see whether
        she speaks french"; "see whether it works"; "find out if
        he speaks russian"; "check whether the train leaves on
        time" syn: determine, check, find out, see, watch,
         learn
     4: learn or discover with certainty
see also:
determine find find out see check insure 
see to it ensure control assure watch 
learn 

[3] : Moby Thesaurus II by Grady Ward, 1.0

77 moby thesaurus words for "ascertain":
   afford proof of, appraise, ask, assure, be informed,
   become acquainted with, bring home to, broaden the mind, catch on,
   certify, cinch, clear up, clinch, consider, contemplate,
   cram the mind, decide, demonstrate, determine, discover,
   dismiss all doubt, ensure, establish, find, find out,
   find out about, fix, follow, follow from, gain knowledge, get,
   get at, get hold of, have a case, hear, hold good, hold water,
   inquire, inspect, insure, interrogate, learn, learn about,
   load the mind, make a decision, make certain, make good,
   make no doubt, make no mistake, make out, make sure, make sure of,
   nail down, observe, pick up information, prove, prove to be,
   prove true, query, question, reassure, remove all doubt, resolve,
   see, see that, see to it, set at rest, settle, settle the matter,
   show, sort out, study, survey, tumble, unearth, view, weigh

Ascertain >> A Words
Ascertain, definition of term: Ascertain
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