n. (pl. -ies) 1 an elaborate composition usu. for full orchestra, and in several movements with one or more in sonata form. 2 an interlude for orchestra alone in a large-scale vocal work. 3 = symphony orchestra. symphony orchestra a large orchestra suitable for playing symphonies etc.
[ ME, = harmony of sound, f. OF symphonie f. L symphonia f. Gk sumphonia (as SYN-, - phonos f. phone sound) ]