Arch

1. To form into an arch; to curve.
2. A chief.
3. Any place covered by an arch; an archway; as, to pass into the arch of a bridge.
4. Chief; eminent; greatest; principal.
5. Any curvature in the form of an arch; as, the arch of the aorta.
6. A flat arch is a member constructed of stones cut into wedges or other shapes so as to support each other without rising in a curve.
7. To cover with an arch or arches.
8. Cunning or sly; sportively mischievous; roguish; as, an arch look, word, lad.
9. To form or bend into the shape of an arch.
10. Any part of a curved line.
11. Usually a curved member made up of separate wedge-shaped solids, with the joints between them disposed in the direction of the radii of the curve; used to support the wall or other weight above an opening. In this sense arches are segmental, round (i. e., semicircular), or pointed.