- 1日出時分、天亮（口語、美式；常見於「from sun-up to sundown 從早忙到晚」）
The time in the early morning when the sun comes up — the same moment as sunrise.
The two words mean the same thing, so the real question is which one to use, and that is a question of feeling rather than meaning. 'Sunrise' can be the beautiful sight — the colours in the sky, the thing you take a photograph of. 'Sun-up' almost never is. Sun-up is a point on the clock, the moment work can begin. That is why it lives mostly inside one phrase: 'from sun-up to ' — meaning all day long, and usually all day working hard. Farmers, soldiers, fishermen, builders. If a person says they worked from sun-up to , they are telling you they were tired.
It has a plain, country, spoken feel, and it is much more common in American English than British. You hear it in old songs, in stories about farm life and the American West, and from older speakers. In a weather report or a science book you would see 'sunrise' instead — nobody 'sun-up is at 5:42'.
The spelling wobbles: sun-up, sunup, and sun up all appear, and none is wrong. Americans often write it closed up as 'sunup'.
Its partner word at the other end of the day is '', which is usually written as one word without a — a small oddness worth remembering.
sun-up 指太陽剛升起的清晨時分，和 sunrise 是同一個時刻。兩個字意思一樣，差別在感覺。sunrise 通常是好看的景象，sun-up 比較像時鐘上的一個時間點，也就是可以開始工作的時候。所以這個字大多只出現在片語「from sun-up to sundown」裡，意思是從早忙到晚。
它的語氣樸素，帶著鄉村的味道，多半是口語，美式英語比英式英語常用。你在老歌、農場或西部的故事裡比較容易聽到，年紀大的人也常這樣說。天氣預報通常會用 sunrise。寫法有 sun-up、sunup 和 sun up 幾種，都可以，美國人常寫成 sunup。
組成sun + up — the sun being up, made into a name for the moment it happens. English does this with several small phrases: a break-up, a set-up, a check-up. Here the picture is simply the sun rising over the edge of the land.
原始詞典資料1 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
這個拼法也被記錄為下列字的變化形：
- sunup
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。