Is it der, die or das Dekadenz?

Why is it die Dekadenz?

Dekadenz ends in -enz, and nouns ending in -enz are feminine: in a German dictionary, 97% of them take die.

Sense 1

die

[1] Decay, degeneration, moral and cultural decline

[1] Verfall, Entartung, sittlicher und kultureller Niedergang

[1] Their behavior testifies to advanced decades
[1] Ihr Verhalten zeugt von fortgeschrittener Dekadenz.

[1] This culture was by no means lacking decade signage
[1] Es fehlte dieser Kultur keineswegs an Dekadenzerscheinungen.

Dictionary entries include material from Wiktionary. Wiktionary