safety curtain

WordReference Random House Unabridged Dictionary of American English © 2026

safe′ty cur′tain, 

1. Theater a sheet of asbestos or other fireproof material that can be lowered just inside the proscenium arch in case of fire, sealing off the backstage area from the auditorium. Also called fire curtain. 

• 1905–10

Collins Concise English Dictionary © HarperCollins Publishers::

safety curtain noun

1. a curtain made of fireproof material that can be lowered to separate the auditorium and stage in a theatre to prevent the spread of a fire