Arch \Arch\, v. t. [imp. & p. p. Arched; p. pr. & vb. n. Arching.]1. To cover with an arch or arches.
2. To form or bend into the shape of an arch.
The horse arched his neck. --Charlesworth.
Source: Webster's Revised Unabridged Dictionary (1913)
Arching \Arch"ing\, n.1. The arched part of a structure.
2. (Naut.) Hogging; -- opposed to sagging.