the.com/decadence

means A state of luxurious indulgence or moral/cultural decline, often used to describe excess that's gorgeous on the surface and rotting underneath.

from Traces back through French 'décadence' to Medieval Latin 'decadentia,' built from the Latin verb 'decadere' — 'to fall down' or 'fall away' (de- 'down' + cadere 'to fall,' the same root that gives us 'cadence' and 'cascade'). So the word itself is a tiny act of falling: empires, morals, and soufflés all 'decadere' when they collapse under their own richness. By the 18th and 19th centuries, writers were using it specifically to describe civilizations past their prime — ripe, ornate, and quietly rotting.