The phrase '甚嚣尘上' is formed through a direct combination of its four characters: '甚' meaning 'very' or 'extreme' intensifies '嚣' meaning 'clamor' or 'noise,' while '尘' meaning 'dust' pairs with '上' meaning 'rising' to depict dust ascending. It originates from a literal description in the ancient text "Zuozhuan" of a chaotic battlefield scene with excessive noise and dust, which later evolved into a figurative idiom representing widespread rumors or public uproar.