The word 'proscenium' is a real word and can be used in written English.
It is most commonly used to refer to the area of a theater stage bordered by the frame of the arch. For example: The audience was seated in front of the proscenium, eagerly awaiting the start of the performance.
Dictionary
proscenium
noun
The stage area between the curtain and the orchestra.
synonyms
Exact(59)
But when the great day arrived, the theatre's golden proscenium arch was still in pieces on the floor, alongside plywood boards, while scaffolding rose the full 28-metre (92-foot) height of its dome.
One is the theatre architecture: the Royal Court has a simple but very forceful proscenium arch, and I always write imagining that.
Mr Gergiev went on to blame the failure in Cardiff on the "horizontal shape of the proscenium".
There is a spotlight, a proscenium stage and a marquee out front.
But the overtitles projected on the proscenium arch were unnervingly out of synch.
Indeed, part of the success of proscenium theatres has been that the stage area, where fires are most likely to start, can be sealed off from the house through the use of a fire curtain that closes the arch.
But there is one variety of end stage theatre that intentionally puts the stage in a separate volume of space from that occupied by the house: the proscenium, or "Italian style," theatre.
The theatre, designed by Giovanni Battista Aleotti and built in 1618 (but not used until 1628, to celebrate the marriage of a Medici daughter to a Farnese son), was the first proscenium theatre to be designed for movable scenery and is the earliest large-scale indoor theatrical facility to have survived.
His stage did away with the front curtain (for the first time on the modern French stage), and it extended out from the proscenium arch to surround the audience on three sides.
In 1664 65 the old theatre was demolished and a new one built by Jan Vos in the Italian Baroque style with a proscenium and an elaborate system of wings, traps, flies, and machines.
Similar(1)
The two fundamentally opposing conceptions of theatre design proscenium style and open stage predominate.
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