秋

秋 (qiū) means 'autumn / fall.' On its own it is mostly literary or used in compounds (秋天 autumn, 秋季 autumn season, 中秋 Mid-Autumn, 春秋 spring and autumn / the seasons of a year / a historical era). In daily conversation, native speakers almost always say 秋天 (qiūtiān) for 'autumn,' just as they say 春天, 夏天, 冬天.

Culturally, 秋 is associated with harvest, cooling weather, falling leaves, and the Mid-Autumn Festival (中秋节, when families gather to eat mooncakes under the full moon). It also carries a poetic flavor of melancholy in classical literature — 秋风 (qiūfēng, autumn wind) is a stock image of loneliness.