a group of people playing musical instruments (including stringed instruments) together
symphony
Cases of word usage
1) a short, thin stick as used by the conductor of an orchestra (baton)
2) a musical composition for one or more solo instruments supported by an orchestra (concerto)
3) to compose, arrange, score, (music) for an orchestra (orchestrate)
4) a (long) composition in (usually) three or four parts (called 'movements') for an orchestra (symphony)