守不住的地方
這一支就是核心畫面的字面版本：真的有一個地方擋不住。
adjective · C1
Impossible, or very hard, to protect from attack.
守不住的；難以防守的
核心畫面
Picture a wall with nothing behind it: low ground, open on three sides, every path leading straight in. You can put people on that wall, but it will not hold. That is the picture the word carries, and it works just as well when the thing being held is not a place but an argument. Someone asks you to account for what was done, you start to speak, and there is no line that holds.
可以想成一道守不住的牆：地勢低、三面開闊，每條路都直通進來。你要派人站上去也行，但擋不住。這個字帶的就是這幅畫面。而…更多收起
可以想成一道守不住的牆：地勢低、三面開闊，每條路都直通進來。你要派人站上去也行，但擋不住。這個字帶的就是這幅畫面。而同一幅畫面換到說話上一樣好用：別人要你交代這件事，你開口了，可是沒有一句話撐得住。From the word’s history
Simply in- plus defensible: not able to be held. The packet's etymology tree shows the same negative prefix that English took from Latin through Middle English, added to the ordinary word for something that can be defended.
就是 in-（不）加上 defensible（守得住的、辯護得了的）。這個否定字首是從拉丁文經中古英語進到英文的。所以整個字字面上只說一件事：守不住。
Wiktionary etymology tree supplied in this packet (source_ref kaikki:3f6f69a190036ae4:1217847407): in- + defensible
Two branches
講不過去的事
把「守不住」從地形搬到話語上：要替這件事講話，一句都撐不住。這是一條理解上的連結，不是說哪個意思先出現。
adjective · C1
So bad or so wrong that there is no good reason for it and nobody can excuse it, even if they try to explain it away.
無法辯解的；說不過去的