人垮下來的姿勢
這一組就是核心畫面直接用在人身上：身體不再撐著自己，背和肩膀垮下去。動詞講這個動作，名詞把這個樣子叫出名字，及物的用法則是讓身體的某一部分垂下去。
verb · B2
To stand, sit, or walk with your back curved and your shoulders and head bent forward, so that your body looks loose and droopy instead of upright.
駝背；癱著坐或站
核心畫面
You can picture slouch as something that has stopped holding itself up. The back rounds, the shoulders roll forward, the head drops a little, and the whole shape settles downward in a soft curve. Nothing is broken and nothing has fallen over — it is just not carrying its own weight any more. Hold that one picture and the rest follows: a person sitting or walking that way, the name for that shape, a hat brim or a plant hanging in the same soft droop, and a head let down onto a desk. Even the compliment no slouch works off it, by saying that a person is the opposite of that drooping shape.
可以想成一個「撐不住了、垮下來」的形狀。背彎成一條弧線，肩膀往前掉，頭也低了一點，整個東西往下沉。它沒有斷，也沒有倒…更多收起
可以想成一個「撐不住了、垮下來」的形狀。背彎成一條弧線，肩膀往前掉，頭也低了一點，整個東西往下沉。它沒有斷，也沒有倒，只是不再撐住自己的重量。抓住這一個畫面，其他用法就接得上：一個人這樣坐著或走著、這個姿勢本身的名字、帽緣或植物一樣軟軟地垂下去、把頭垂到桌上。連稱讚人的 no slouch 也是從這裡來的——它說一個人正好不是這個垮下來的樣子。From the word’s history
The source marks the origin as unclear. One suggested line runs through Middle English slugge and Old Norse slokr, 'a lazy fellow', with Swedish sloka 'to droop, wilt' and slak 'slack' alongside it. If that line is right, the oldest idea in the word is slackness — something loose that hangs — which is exactly the modern picture.
資料把這個字的來源標為「不確定」。一種說法是它經過中古英文 slugge、古北歐語 slókr（懶散的人），旁邊還有瑞典語 sloka（垂下、枯萎）和 slak（鬆的）。如果這條線成立，這個字最底層的意思就是「鬆」——鬆掉的東西就會垂下來，這正好就是今天的畫面。因為來源標明不確定，這裡當成一個記憶的線索，不是定論。
Wiktionary via local kaikki extract, source_ref kaikki:3f6f69a190036ae4:665330949 (etymology explicitly marked "Unclear. Perhaps…")
Three branches
東西垂下來、塌下去
把核心畫面從人移到物。本來該撐著的東西軟掉了，於是掛成一條往下的弧線——帽緣、植物、紙袋都可以這樣塌。
noun · C1
A downward droop in a thing that has lost its shape or is meant to hang softly — for example the soft fall of a hat brim, or a plant bending over.
（東西的）垂下、下塌
把垮下來的樣子倒過來用：稱讚
先把「垮著的人」讀成「懶、沒本事」，再整個否定掉。說 no slouch，就是說這個人完全不是那個樣子——因此很行。稱讚是從畫面的反面來的。
noun · C1
If someone is no slouch at something, they are very good at it. The expression is almost always used in this negative form, and it praises the person by saying they are far from weak or lazy at that thing.
很行；一點都不差