χαλινός refers to the bit or bridle used to control a horse—the metal piece inserted in the mouth that allows the rider to guide and restrain the animal. James uses it in his famous illustration of the tongue's power in James 3:3: 'If we put bits (χαλινοὺς) into the mouths of horses so that they obey us, we guide their whole bodies.' The point is that a small instrument can control a large, powerful creature. Curiously, the word appears again in Revelation 14:20 in a literal sense: blood flowing from the winepress of God's wrath reaches 'as high as a horse's bridle (χαλινῶν τῶν ἵππων)' for 1,600 stadia—a horrifying image of judgment.