身體被猛拉，停不下來
核心畫面的字面版本：被扯動的就是一具真正的身體。
verb · C1
If a person's body, or a part of it, convulses, it jerks and shakes hard and they cannot stop it or control it — for example during a seizure, or when someone is crying very hard.
抽搐；劇烈抖動
核心畫面
Something takes hold of a body and it about, and the body cannot stop it. Picture shoulders jerking with sobs, or a leg jumping on its own after a long run: the movement is hard, sudden, and nobody chose it. Every use of convulse keeps those two parts — violent shaking, and no control. What changes is what is doing the pulling (a muscle, a feeling, a crisis) and how big the body is (a person, a crowd, a whole country).
「convulse」可以想成：有東西抓住一具身體，把它猛力扯動，而身體自己停不下來。畫面像是哭到肩膀一抖一抖，或長跑…更多收起
「convulse」可以想成：有東西抓住一具身體，把它猛力扯動，而身體自己停不下來。畫面像是哭到肩膀一抖一抖，或長跑之後小腿自己跳起來——動作又急又重，而且不是本人決定的。這個字的每一種用法都保留這兩件事：劇烈的抖動，以及不受控制。會變的只有兩點：在拉扯的是什麼（是肌肉、是情緒，還是一場危機），以及那具「身體」有多大（一個人、一群人，或是一整個國家）。From the word’s history
Wiktionary traces convulse to Latin convellere, from com- (together, thoroughly) plus vellere (to pluck, to pull). The literal sense is to pull hard at something, which is exactly the picture the modern word keeps.
來源資料把這個字追到拉丁文 convellere：com-（徹底、一起）加上 vellere（拔、猛拉），字面就是「用力扯動」。這條線索跟現代的畫面完全對得上——不管扯的是肌肉、情緒還是整個社會，被扯的一方都只能跟著抖。
Wiktionary entry for convulse; packet etymology_text ("From Latin convulsus, past participle of convellere ... from com- + vellere"), source_ref kaikki:3f6f69a190036ae4:767107101:9575
Two branches
被放大的那具身體：整個社會
把被扯動的對象放大：不是一個人的身體，而是一個城鎮、國家或市場被當成一具身體。這是概念上的延伸，不是另一條歷史來源。
verb · C2
If something such as a war, a strike or a scandal convulses a country, a market or a group, it shakes it badly and throws it into trouble and confusion. The same idea is also written the other way round, with the country or group as the subject: the region was convulsing with unrest.
使動盪不安