An inseparable prefix standing opposite to εὖ- (well, good), adding notions of difficulty, misfortune, or badness to the words it modifies. It can destroy the good sense of a word or intensify its negative meaning. Remarkably, it can attach even to words that already express negation, creating emphatic double negatives. Poetic usage exploits it for strong contrasts, as in 'Paris the ill-Paris' or 'marriage that is a bad marriage.' Before certain consonant clusters (στ, σθ, σπ, σφ, σχ), the final sigma drops. The prefix has cognates in Sanskrit and other Indo-European languages, all carrying similar negative force.