■ noun
1》 [treated as sing. or plural ] a group of instrumentalists, especially one combining string, woodwind, brass, and percussion sections.
2》 (also ~ pit ) the part of a theatre where the ~ plays, typically in front of the stage and on a lower level.
3》 N. Amer. the stalls in a theatre.
4》 the semicircular space in front of an ancient Greek theatre stage where the chorus danced and sang.
Derivatives
~l adjective
~lly adverb
Origin
C17: via L. from Gk orkhēstra , from orkheisthai 'to dance'.