One way to hold percolate: think of a layer of sand, soil or rock, and one drop of water on top of it. The drop does not run. It is held up by a million tiny holes, so it edges round one grain, then the next, and takes hours or years to come out the other side. Nothing pushes it and nobody directs it; the material itself decides how slow the journey is. Every use of percolate in English seems to keep that same picture — something making its slow way through something full of small gaps.
From the word’s history
The evidence packet traces percolate to Latin percōlāre, from per ('through') plus cōlāre ('to strain'), itself from cōlum, 'a strainer'. The core image is close to that literally: something passing through a strainer.
附上的維基詞典資料指出，percolate 來自拉丁文 percōlāre：per 是「穿過」，cōlāre 是「過濾」，而 cōlum 就是「濾網」。這條線索幾乎就是核心畫面本身——東西穿過一層濾網。
Wiktionary entry supplied in the evidence packet (source_ref kaikki:3f6f69a190036ae4:900231262)
登入就可以看每一支怎麼連回核心畫面。