solstice
noun [ C ] uk/ˈsɒl.stɪs/ us/ˈsɑːl.stɪs/ /ˈsoʊl.stɪs/
至,至点
either of the two occasions in the year when the sun is directly above either the furthest point north or the furthest point south of the equator that it ever reaches. These are the times in the year, in the middle of the summer or winter, when there are the longest hours of day or night
the summer/winter solstice 夏/冬至
Compare: equinox