Sikhluth (H5531) means folly, foolishness, or madness. Derived from the verb sakal (to act foolishly), it appears 7 times in Ecclesiastes as part of Qohelet's exploration of wisdom and folly. It represents not merely intellectual error but the willful rejection of God's order.
Qohelet deliberately 'gave his heart to know wisdom and to know madness and folly' (Eccl 1:17) — a systematic investigation into what constitutes genuine wisdom. Sikhluth is the negative pole. In Proverbs and Ecclesiastes, folly is not accidental stupidity but a moral orientation — the posture of a life lived apart from the fear of God. Psalm 14:1 makes this explicit: 'The fool says in his heart, There is no God.'
Sikhluth appears only in Ecclesiastes, making it characteristic vocabulary of Qohelet's philosophical exploration. The OT concept of folly is fundamentally theological — not an IQ issue but an issue of orientation toward God. The 'fear of the LORD is the beginning of wisdom' (Prov 9:10) — and sikhluth is life without that beginning.