porte-cochère

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A carriage entrance leading through a building or wall into an inner courtyard.
• noun A roofed structure covering a driveway at the entrance of a building to provide shelter while entering or leaving a vehicle.

from The Century Dictionary.

• noun A carriage-entrance in a building; a gate and passage for carriages leading through a building, as a town-house or hotel, from the street to an interior court.

from the GNU version of the Collaborative International Dictionary of English.

• noun (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-cochère. Also, a porch over a driveway before an entrance door.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a carriage entrance passing through a building to an enclosed courtyard
• noun canopy extending out from a building entrance to shelter those getting in and out of vehicles