1911 Encyclopædia Britannica/Portico
PORTICO (Ital. for “ porch,” Lat. porticus), a term in architecture for the covered entrance porch to a building, which is carried by columns, and either constitutes the whole front of the building, as in the Greek and Roman temples, or forms an important feature, as the portico of the Pantheon at Rome attached to the rotunda. A circular projecting portico, such as those to the north and south transepts of St Paul's Cathedral, and that which forms the west entrance of St Mary le Strand, is known as cyclostyle. The term porticus is used to distinguish the entrance portico in an amphiprostylar or peripteral temple from that behind which is called the posticum.