A Greek adjective meaning foolish, stupid, dull, flat (of taste). The root of the English word 'moron.' In the New Testament, it describes not merely intellectual deficiency but spiritual and moral stupidity — the failure to perceive what is obviously true about God. It can also describe things that appear foolish by human standards but are actually divine wisdom.
Jesus uses mōros in stark warning: 'Whoever says "You fool!" shall be liable to the hell of fire' (Matthew 5:22) — yet He Himself calls the Pharisees 'blind fools' (Matthew 23:17). The difference is not hypocrisy but authority: only the Judge of all can pronounce someone's life truly foolish. The parable of the foolish virgins (Matthew 25:2) warns against spiritual unpreparedness. But Paul flips the word radically: 'the foolishness (mōria) of God is wiser than men' (1 Corinthians 1:25). The Cross appears mōros to the world — a crucified Messiah is absurd — but this 'foolishness' is God's wisdom that shatters human pretension. God chose what the world considers moronic to shame the wise.