Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
symphōnĭăcus, a, um, adj.,  =  συμφωνιακός. 
- I.  In gen., of or belonging to concerts or to music: pueri, i. e. singingboys, choristers, Cic. Mil. 21, 55: servi, id. Div. in Caecil. 17, 55: homines, id. Verr. 2, 5, 25, § 64: artes, Arn. 2, 73.
 
- II.  Herba, a plant, called also hyoscyamos, henbane, Pall. 3, 12. 8; Veg. 3, 68; App. Herb. 4.