autumn equinox
(亦作autumnal equinox)
noun
1- the equinox in autumn, on about 22 September in the northern hemisphere and 20 March in the southern hemisphere秋分（北半球约在9月22日, 南半球约在3月20日）。
1.1
- Astronomy the equinox in September【天文】（9月的）秋分。