Source : Webster's Revised Unabridged Dictionary (1913)

Arciform \Ar"ci*form\, a. [L. arcus bow + -form.]
   Having the form of an arch; curved.

Source : WordNet®

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