肃杀

In classical Chinese cosmology, autumn was paired with the metal element (金) and with execution - 'autumn' was the season for carrying out death sentences. 肃杀之气 ('the qi of severe killing') captures both the dying landscape and the political-judicial chill of late autumn.

Literary, sets a heavy mood. Reach for it in writing about autumn, courtrooms, war zones, dictatorships - anywhere you want a tone of cold, oppressive severity.