身體上的那個記號
照字面用那個記號，包括用它的形狀去命名別的東西。
noun · B2
The small hollow, or sometimes small raised mark, in the middle of your stomach. It is left where the cord that joined you to your mother before birth was cut. All placental mammals have one.
肚臍
核心畫面
Picture the one small mark that sits exactly in the middle of the front of a body — the knot left where you were once joined to your mother. Two facts about it do all the work. First, it is dead centre, so anything with a middle can borrow the word. Second, it is unmistakably yours, and it is the one spot you have to bend your head to look at, which is why staring at it became a joke about people who only look inward. Even the orange is named from the same mark: a small round scar at one end that looks like a little navel.
navel 可以想成身體正面正中央的那個小記號，一個曾經和母親相連、後來留下的結。有兩件事把後面的用法全帶起來了。第…更多收起
navel 可以想成身體正面正中央的那個小記號，一個曾經和母親相連、後來留下的結。有兩件事把後面的用法全帶起來了。第一，它在正中央，所以任何有「中心」的東西都能借這個字。第二，它是自己身上的東西，而且要低頭彎腰才看得到——盯著它看，於是變成了一句笑話，用來說那些只往內看的人。連橙子也是因為這個記號得名：蒂頭對面有個小圓疤，看起來就像一個小肚臍。From the word’s history
The source entry traces navel back through Old English nafola to a root meaning 'hub, navel' — the same word family as the centre of a wheel. A word that once covered both the middle of a body and the middle of a wheel already carries the idea of a centre.
來源資料把 navel 一路追到古英語 nafola，再上溯到一個同時表示「肚臍」和「輪轂（車輪中心）」的詞根。也就是說，這個字很早就同時指身體的中心和輪子的中心。「中央那一點」這個想法，本來就在字裡面。這是一條可以拿來記憶的線索，不必把它當成後面每個用法的直接來源。
Wiktionary/kaikki snapshot 3f6f69a190036ae4, entry 'navel' (noun), etymology_text: Middle English navel, Old English nafola, from Proto-Germanic *nabalô, from PIE *h₃nóbʰōl, diminutive of *h₃nebʰ- ('hub; navel').
Three branches
正中央那一點
把「身體的正中央」搬到地方或風景上。
noun · C1
The middle point of a place or a thing, thought of as its centre. This use is literary and is almost always followed by 'of'.
（某處的）正中心
低頭盯著自己的肚臍
用「看肚臍」這個動作，比喻只看自己。
noun · C1
To spend too much time thinking about your own feelings and problems instead of looking at what is happening around you or doing something about it. People usually say it in a joking way.
只顧著想自己的事；自我耽溺