Proscenium Arch(redirected from proscenium arches)
Also found in: Dictionary, Thesaurus.
the architectural frame that forms a portal opening to the stage and separates it from the audience. In the modern theater the proscenium arch is usually rectangular. Temporary (and often movable) decorative proscenium arches are also used, both as a part of the stage set and as a means for reducing the size of the stage area.