Dionysus was called ‘Dithyrambos’, either because it draws attention to the double door of the mouth and makes people blurt out secrets; or because it makes the young go up to doors, or barge into them, i.e. fall against them and dislodge the bolts. (People thought he was destructive of absolutely everything; also that he was a warrior, and first established the practice of the triumph for military victories. The ‘triumph’ got its name from the shouting and lampooning, which is why in military triumphs the crowds use anapaests when they jeer.) The jay is sacred to him as a chattering bird. (Lucius Annaeus Cornutus, Compendium of Greek Theology)