Definition of "discern"

discern

verb
third-person singular simple present discerns, present participle discerning, simple past and past participle discerned
1. (transitive) To detect with the senses, especially with the eyes.
  Quotations
  Meanwhile the brig had altered her tack, and was moving slowly to the east. Three hours later and the keenest eye could not have discerned her top-sails above the horizon.
  1875, Jules Verne you are no HELP!, chapter 1, in The Survivors of the Chancellor‎, archived from the original on 12 April 2012
2. (transitive) To perceive, recognize, or comprehend with the mind; to descry.
  Quotations
  If they discern any evidences of wrong-going in any direction that I have indicated, they will acknowledge that I had reason in what I wrote. If they discern no such thing, they will consider me altogether mistaken.
  1842, Charles Dickens, American Notes for General Circulation‎, archived from the original on 19 May 2011
3. (transitive) To distinguish something as being different from something else; to differentiate or discriminate.
  Quotations
  The severity of judgement, they say, makes men censorious and unapt to pardon the errors and infirmities of other men: and on the other side, celerity of fancy makes the thoughts less steady than is necessary to discern exactly between right and wrong.
  1651, Thomas Hobbes, Leviathan‎, archived from the original on 7 June 2011
4. (intransitive) To perceive differences.