(~s)
1.
An ~ is a large group of musicians who play a variety of different instruments together. Orchestras usually play classical music.
...the Royal Liverpool Philharmonic Orchestra.
N-COUNT: oft in names
see also chamber ~ , symphony ~
2.
The ~ or the ~ seats in a theatre or concert hall are the seats on the ground floor directly in front of the stage. (mainly AM; in BRIT, usually use stalls )
N-SING: usu the N, N n