排水系統最低的坑
這一支就是核心本身：人為地把地面做斜，讓所有液體流到一個坑裡，方便抽走或清掉。
noun · C1
The lowest point of a drainage system: a pit, hole or dip that water, waste liquid or oil runs down into and collects in, so that it can be pumped away or cleaned out.
集水坑；集污坑
核心畫面
Hold one picture for sump: the lowest place, where liquid ends up because it has nowhere further to fall. A floor is , a shaft goes down, a cave dips, an engine sits above a pan, and everything wet runs to that one low spot and stays there. Every use of the word is that spot seen in a different building or machine. The word is a of swamp, which fits: both are about water standing in a low place. What changes from use to use is only what the low place is part of, and whether the liquid is there to be pumped out, to be used again, or to block your way.
sump 可以用一個畫面拿住：最低的那個地方，液體流到那裡就沒得再低了。地板做成斜的，礦坑往下挖，洞穴通道下凹，引擎…更多收起
sump 可以用一個畫面拿住：最低的那個地方，液體流到那裡就沒得再低了。地板做成斜的，礦坑往下挖，洞穴通道下凹，引擎底下墊著一個盤子——所有會流的東西最後都停在那一點。這個字的每一種用法，都是同一個「最低點」放在不同的建築或機器裡。它跟 swamp（沼澤）同源，畫面正好接得上：都是水停在低處。不同的只是那個低處屬於什麼系統，以及那些液體是要被抽走、要再用，還是擋住你的去路。From the word’s history
From Middle English sompe, from Middle Dutch or Middle Low German sump, ultimately from Proto-Germanic *sumpaz. It is a doublet of swamp.
來自中古英文 sompe，再往上是中古荷蘭文或中古低地德文的 sump，最後回到原始日耳曼語 *sumpaz。它跟 swamp 是同源分出來的兩個字，所以「水停在低窪處」這個畫面，從最早就在這個字裡面。
Wiktionary entry supplied in this packet (source_ref kaikki:3f6f69a190036ae4:1140205910)
Three branches
引擎底下的油槽
引擎也是一套讓液體往下流回來的系統，最底下那個接住機油的容器，就沿用了同一個名字。字典把這個用法標為英式英文。
noun · C1
In a car or other engine, the metal container at the bottom that holds the engine's supply of oil.
油底殼
洞穴裡被水填滿的一段
一樣是水積在最低處，只是這次人在洞裡面，而水已經把整段通道從牆到頂填滿，變成擋路的東西。
noun · C2
In caving: a length of cave passage that is completely full of water, so the only way past it is to swim or dive through.
洞穴中的積水段