Source : Webster's Revised Unabridged Dictionary (1913)

Portico \Por"ti*co\, n.; pl. {Porticoes}or {Porticos}. [It., L.
   porticus. See {Porch}.] (Arch.)
   A colonnade or covered ambulatory, especially in classical
   styles of architecture; usually, a colonnade at the entrance
   of a building.