衝上天的那根水柱
這一族直接就是核心畫面本身：自然界的那根水柱，借來形容別的東西的水柱，以及把它當成動作來用。
noun · B2
A natural hot spring that suddenly shoots boiling water and steam high into the air out of a hole in the ground, often doing this again and again with a gap in between.
間歇泉
核心畫面
You can think of geyser as boiling water that has been held down until it cannot be held any longer. Pressure builds under the ground, and then the whole column goes straight up through one small hole, all at once. Hold on to the shape and the force — narrow, upward, sudden — because that is what gets carried over everywhere else the word turns up, including onto a machine in a bathroom.
geyser 可以想成「被壓住的滾水終於壓不住了」。地下的壓力一直累積，然後整柱水從一個小洞直直衝上天，一次噴完。要…更多收起
geyser 可以想成「被壓住的滾水終於壓不住了」。地下的壓力一直累積，然後整柱水從一個小洞直直衝上天，一次噴完。要記住的是那個形狀和那股力道：又細、朝上、突然。這個畫面後來被借到別的地方去，連浴室裡那台會噴熱水的機器也是這樣得名的。From the word’s history
From Icelandic Geysir, the name of one particular Icelandic hot spring, from the verb geysa, to gush. One spring's own name became the word for all of them.
這個字來自冰島語 Geysir，本來是冰島某一座噴泉的名字，而它又來自動詞 geysa（噴出）。也就是說，一個專有名詞先變成通稱，才有今天的 geyser。
Wiktionary entry for geyser (etymology section), kaikki extract 3f6f69a190036ae4:617288762
Two branches
會噴熱水的機器
把同一個畫面搬進浴室：一台會突然給你滾燙熱水的機器，就直接借了那座冰島噴泉的名字。
noun · B2
A machine that heats water in a home: in British English one fixed to the wall above a bath or a sink, and in South Africa and South Asia the ordinary everyday word for a household water heater or boiler.
（家用）熱水器