orchestras is a form of:

Orchestra



noun
1.
កន្លែងវង់ភ្លេង (ក្នុងរោងល្ខោន), conduct an orchestra វង់ភ្លេង (វង់តន្ត្រី, តុរិយាង្គ), seats in the orchestra ជាន់ក្រោមនៃរោងកុន ល្ខោន ។ល។
ENGLISH MEANING
noun
1.
The space in a theater between the stage and the audience; -- originally appropriated by the Greeks to the chorus and its evolutions, afterward by the Romans to persons of distinction, and by the moderns to a band of instrumental musicians.
2.
The place in any public hall appropriated to a band of instrumental musicians.
3.
Loosely: A band of instrumental musicians performing in a theater, concert hall, or other place of public amusement.
4.
Strictly: A band suitable for the performance of symphonies, overtures, etc., as well as for the accompaniment of operas, oratorios, cantatas, masses, and the like, or of vocal and instrumental solos.
5.
A band composed, for the largest part, of players of the various viol instruments, many of each kind, together with a proper complement of wind instruments of wood and brass; -- as distinguished from a military or street band of players on wind instruments, and from an assemblage of solo players for the rendering of concerted pieces, such as septets, octets, and the like.
6.
The instruments employed by a full band, collectively; as, an orchestra of forty stringed instruments, with proper complement of wind instruments.