n. & v.
n. 1 a a curved structure as an opening or a support for a bridge, roof, floor, etc. b an arch used in building as an ornament. 2 any arch-shaped curve, e.g. as on the inner side of the foot, the eyebrows, etc.
v. 1 tr. provide with or form into an arch. 2 tr. span like an arch. 3 intr. form an arch.
[ ME f. OF arche ult. f. L arcus arc ]