This abstract noun denotes folly or foolish behavior, the opposite of wisdom that Ecclesiastes repeatedly examines. Qoheleth includes it in his comprehensive exploration: 'I applied my heart to know wisdom and to know madness and folly.' The word appears multiple times in Ecclesiastes, always as something to be understood rather than pursued. Occasionally spelled with shin rather than samekh (a scribal variation), it represents the negative pole in wisdom's moral universe. Folly isn't innocent fun but destructive stupidity—the kind that wrecks lives, relationships, and communities. The Preacher studies it carefully to understand human behavior under the sun.