Flies and Fly sheet

Flies noun - Theater) the space over the stage (out of view of the audience) used to store scenery (drop curtains.

Fly sheet is a synonym for flies. In some cases you can use "Fly sheet" instead a noun "Flies".

Fly sheet noun - Flap consisting of a piece of canvas that can be drawn back to provide entrance to a tent.

Flies is a synonym for fly sheet. Sometimes you can replace term "Flies" with "Fly sheet", this terms are similar.