porticus noun2 •An ancient Roman colonnade, arcade, or portico.The upper end of the crypto-porticus forms its own room looking out to the hippodrome, the vineyards, and the mountains; next to it is a room that enjoys the sun, especially during winter. — 2014 •A small room in a church, commonly forming extensions to the north and south sides of it, giving the building a cruciform plan, which may function as a chapel, rudimentary transept or burial place.Only the nave survives but it is not difficult to imagine the apse at the east end, and the small porticuses to the north and south. — 2018 formsporticuses