退廃 （タイハイ） (moral) decay, (social) decline, decadence, corruption, degeneration, deterioration, decline (in prosperity)

退勢 （タイセイ） decline, one's declining fortunes, decay

廃退 （ハイタイ） (moral) decay, (social) decline, decadence, corruption, degeneration, deterioration, decline (in prosperity), falling into disuse