n. Properly, a series of arches supported on piers or pillars.n. A simple arched opening in a wall.n. A vault or vaulted place.n. Specifically, in some cities, a long arched passageway; a covered avenue, especially one that is lined with shops.n. In anatomy and zoology, those portions of the cranium having an arch-like structure and running from the postero-external to the orbital region.