The Hebrew word naval means a fool in the moral and spiritual sense — one who is godless, senseless, or wicked. This is not intellectual stupidity but deliberate refusal to acknowledge God and live accordingly. The classic statement 'the fool has said in his heart there is no God' (Psalm 14:1) uses a related term, but naval describes the same reality of practical atheism and moral depravity.
Naval in the Old Testament is a serious moral and theological category. The most famous bearer of this name is Nabal in 1 Samuel 25, whose wife Abigail explicitly interprets his name as his character: 'his name is Fool, and folly goes with him.' The naval is not merely unintelligent but actively hostile to wisdom, righteousness, and the fear of God. In the prophets, Israel in her apostasy becomes the nation that has acted foolishly toward God. The contrast throughout wisdom literature is between the wise (chakam) and the fool (naval) — two trajectories of life, one toward God and flourishing, one toward ruin.