Source : Webster's Revised Unabridged Dictionary (1913)

Open \O"pen\ v. t. [imp. & p. p. {Opened}; p. pr. & vb. n.
   {Opening}.] [AS. openian. See {Open},a.]
   1. To make or set open; to render free of access; to unclose;
      to unbar; to unlock; to remove any fastening or covering
      from; as, to open a door; to open a box; to open a room;
      to open a letter.

            And all the windows of my heart I open to the day.
                                                  --Whittier.

   2. To spread; to expand; as, to open the hand.

   3. To disclose; to reveal; to interpret; to explain.

            The king opened himself to some of his council, that
            he was sorry for the earl's death.    --Bacon.

            Unto thee have I opened my cause.     --Jer. xx. 12.

            While he opened to us the Scriptures. --Luke xxiv.
                                                  32.

   4. To make known; to discover; also, to render available or
      accessible for settlements, trade, etc.

            The English did adventure far for to open the North
            parts of America.                     --Abp. Abbot.

   5. To enter upon; to begin; as, to open a discussion; to open
      fire upon an enemy; to open trade, or correspondence; to
      open a case in court, or a meeting.

   6. To loosen or make less compact; as, to open matted cotton
      by separating the fibers.

   {To open one's mouth}, {to speak}.

   {To open up}, to lay open; to discover; to disclose.

            Poetry that had opened up so many delightful views
            into the character and condition of our ``bold
            peasantry, their country's pride.''   --Prof.
                                                  Wilson.