·noun Any part of a curved line.
II. Arch ·noun A Chief.
III. Arch ·vt To cover with an arch or arches.
IV. Arch ·adj Chief; eminent; greatest; principal.
V. Arch ·vt To form or bend into the shape of an arch.
VI. Arch ·vi To form into an arch; to Curve.
VII. Arch ·noun Any curvature in the form of an arch; as, the arch of the aorta.
VIII. Arch ·adj Cunning or sly; sportively mischievous; roguish; as, an arch look, word, lad.
IX. Arch ·noun Any place covered by an arch; an archway; as, to pass into the arch of a bridge.
X. Arch ·noun 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.
XI. Arch ·noun 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.