The Collaborative International Dictionary of English v.0.48:

Porte-cochere \Porte"-co`ch[`e]re"\, n. [F. See Port a gate,
   and Coach.] (Arch.)
   A large doorway allowing vehicles to drive into or through a
   building. It is common to have the entrance door open upon
   the passage of the porte-coch[`e]re. Also, a porch over a
   driveway before an entrance door.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Carriage \Car"riage\, n. [OF. cariage luggage, carriage,
   chariage carriage, cart, baggage, F. charriage, cartage,
   wagoning, fr. OF. carier, charier, F. charrier, to cart. See
   Carry.]
   1. That which is carried; burden; baggage. [Obs.]
      [1913 Webster]

            David left his carriage in the hand of the keeper of
            the carriage.                         --1. Sam.
                                                  xvii. 22.
      [1913 Webster]

            And after those days we took up our carriages and
            went up to Jerusalem.                 --Acts. xxi.
                                                  15.
      [1913 Webster]

   2. The act of carrying, transporting, or conveying.
      [1913 Webster]

            Nine days employed in carriage.       --Chapman.
      [1913 Webster]

   3. The price or expense of carrying.
      [1913 Webster]

   4. That which carries of conveys, as:
      (a) A wheeled vehicle for persons, esp. one designed for
          elegance and comfort.
      (b) A wheeled vehicle carrying a fixed burden, as a gun
          carriage.
      (c) A part of a machine which moves and carries of
          supports some other moving object or part.
      (d) A frame or cage in which something is carried or
          supported; as, a bell carriage.
          [1913 Webster]

   5. The manner of carrying one's self; behavior; bearing;
      deportment; personal manners.
      [1913 Webster]

            His gallant carriage all the rest did grace.
                                                  --Stirling.
      [1913 Webster]

   6. The act or manner of conducting measures or projects;
      management.
      [1913 Webster]

            The passage and whole carriage of this action.
                                                  --Shak.
      [1913 Webster]

   Carriage horse, a horse kept for drawing a carriage.

   Carriage porch (Arch.), a canopy or roofed pavilion
      covering the driveway at the entrance to any building. It
      is intended as a shelter for those who alight from
      vehicles at the door; -- sometimes erroneously called in
      the United States porte-coch[`e]re.
      [1913 Webster]

WordNet (r) 3.0 (2006):

porte-cochere
    n 1: a carriage entrance passing through a building to an
         enclosed courtyard
    2: canopy extending out from a building entrance to shelter
       those getting in and out of vehicles