(astronomy) the angular distance of a celestial point measured westward along the celestial equator from the zenith crossing; the right ascension for an observer at a particular location and time of day
例句
用作缩略词 (abbr.)
There's a record entry for this year's marathon. 参加本年度马拉松比赛的人数创下最高纪录。
The president made a presentation to the businesswoman of the year. 总统为本年度最成功的女实业家颁发了奖品。
美
