= upper atmosphere n.

In theatres: †(a) (formerly) a stage-box; (b) (now generally) the open part above the dress circle, between that and the ‘gallery.’ In Music Halls…

a (curved) section of seating in a theatre, opera house, etc., whose occupants were originally expected to wear formal dress; (now usually) the…

North American. The lowest gallery in the auditorium of a theatre, cinema, etc.; a dress circle.

Originally: a gallery, open on one or both sides; a colonnade, a portico; a balcony on the outside of a building (obsolete). Also (formerly obsolete…