The Collaborative International Dictionary of English v.0.48:

Evacuate \E*vac"u*ate\, v. t. [imp. & p. p. Evacuated; p. pr.
   & vb. n. Evacuating.] [l. evacuatus, p. p. of evacuare to
   empty, nullify; e out + vacuus empty, vacare to be empty. See
   Vacate.]
   1. To make empty; to empty out; to remove the contents of;
      as, to evacuate a vessel or dish.
      [1913 Webster]

   2. Fig.: To make empty; to deprive. [R.]
      [1913 Webster]

            Evacuate the Scriptures of their most important
            meaning.                              --Coleridge.
      [1913 Webster]

   3. To remove; to eject; to void; to discharge, as the
      contents of a vessel, or of the bowels.
      [1913 Webster]

   4. To withdraw from; to quit; to retire from; as, soldiers
      from a country, city, or fortress.
      [1913 Webster]

            The Norwegians were forced to evacuate the country.
                                                  --Burke.
      [1913 Webster]

   5. To make void; to nullify; to vacate; as, to evacuate a
      contract or marriage. [Obs.] --Bacon.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Evacuate \E*vac"u*ate\, v. i.
   1. To let blood [Obs.] --Burton.
      [1913 Webster]

   2. to expel stool from the bowels; to defecate.
      [PJC]

WordNet (r) 3.0 (2006):

evacuate
    v 1: move out of an unsafe location into safety; "After the
         earthquake, residents were evacuated"
    2: empty completely; "evacuate the bottle"
    3: move people from their homes or country
    4: create a vacuum in (a bulb, flask, reaction vessel)
    5: excrete or discharge from the body [syn: evacuate, void,
       empty]