Source : Webster's Revised Unabridged Dictionary (1913)

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.

Arching \Arch"ing\, n.
   1. The arched part of a structure.

   2. (Naut.) Hogging; -- opposed to {sagging}.

Source : WordNet®

arching
     adj : forming or resembling an arch; "an arched ceiling" [syn: {arced},
            {arched}, {arciform}, {arcuate}, {bowed}]