Source : Webster's Revised Unabridged Dictionary (1913)

Know \Know\, v. t. [imp. {Knew}; p. p. {Known}; p. pr. & vb. n.
   {Knowing}.] [OE. knowen, knawen, AS. cn["a]wan; akin to OHG.
   chn["a]an (in comp.), Icel. kn["a] to be able, Russ, znate to
   know, L. gnoscere, noscere, Gr. ?, Skr. jn?; fr. the root of
   E. can, v. i., ken. (?). See {Ken}, {Can} to be able, and cf.
   {Acquaint}, {Cognition}, {Gnome}, {Ignore}, {Noble}, {Note}.]
   1. To perceive or apprehend clearly and certainly; to
      understand; to have full information of; as, to know one's
      duty.

            O, that a man might know The end of this day's
            business ere it come!                 --Shak.

            There is a certainty in the proposition, and we know
            it.                                   --Dryden.

            Know how sublime a thing it is To suffer and be
            strong.                               --Longfellow.

   2. To be convinced of the truth of; to be fully assured of;
      as, to know things from information.

   3. To be acquainted with; to be no stranger to; to be more or
      less familiar with the person, character, etc., of; to
      possess experience of; as, to know an author; to know the
      rules of an organization.

            He hath made him to be sin for us, who knew no sin.
                                                  --2 Cor. v.
                                                  21.

            Not to know me argues yourselves unknown. --Milton.

   4. To recognize; to distinguish; to discern the character of;
      as, to know a person's face or figure.

            Ye shall know them by their fruits.   --Matt. vil.
                                                  16.

            And their eyes were opened, and they knew him.
                                                  --Luke xxiv.
                                                  31.

            To know Faithful friend from flattering foe. --Shak.

            At nearer view he thought he knew the dead.
                                                  --Flatman.

   5. To have sexual commerce with.

            And Adam knew Eve his wife.           --Gen. iv. 1.

   Note: Know is often followed by an objective and an
         infinitive (with or without to) or a participle, a
         dependent sentence, etc.

               And I knew that thou hearest me always. --John
                                                  xi. 42.

               The monk he instantly knew to be the prior. --Sir
                                                  W. Scott.

               In other hands I have known money do good.
                                                  --Dickens.

   {To know how}, to understand the manner, way, or means; to
      have requisite information, intelligence, or sagacity. How
      is sometimes omitted. `` If we fear to die, or know not to
      be patient.'' --Jer. Taylor.