<p><strong>Noun</strong></p><ul><li>Architecture: a curved masonry construction for spanning an opening, consisting of a number of wedgelike stones, bricks, or the like, set with the narrower side toward the opening in such a way that forces on the arch are transmitted as vertical or oblique stresses on either side of the opening.</li><li>An upwardly curved construction, as of steel or timber functioning in the manner of a masonry arch.</li><li>A doorway, gateway, etc., having a curved head; an archway.</li><li>The curved head of an opening, as a doorway.</li><li>Any overhead curvature resembling an arch.</li><li>Something bowed or curved; any bowlike part: the arch of the foot.</li><li>A device inserted in or built into shoes for supporting the arch of the foot.</li><li>A dam construction having the form of a barrel vault running vertically with its convex face toward the impounded water.</li><li>Glassmaking: a chamber or opening in a glassmaking furnace.</li><li>Pot arch.</li></ul><p><strong>Verb</strong></p><ul><li>(Used with object) to cover with a vault, or span with an arch: the rude bridge that arched the flood.</li><li>To throw or make into the shape of an arch or vault; curve: The horse arched its neck.</li><li>(Used without object) to form an arch: elms arching over the road.</li></ul>