日常的誇張說法
把「失去理智」這個概念借來誇大：不是真的在講精神狀態，而是說一件事離常理太遠——可能太瘋狂、太冒險，也可能好得不像話。
crazy; foolish · adjective · C1
Completely crazy or foolish — often in a way that could be risky or wild.
瘋狂的／太扯了
核心畫面
The word started out as a medical and legal term for serious mental illness. English then borrowed it for everyday — a plan, a price, a party can all be 'insane' — and that borrowed use is now by far the common one. Knowing which layer you are in matters: the original layer is dated and can land badly on real people, while the layer is light and friendly.
這個字原本是醫學和法律上的用語，指嚴重的精神疾病。後來英文把它借去做日常的誇飾——一個計畫、一個價錢、一場派對都可以…更多收起
這個字原本是醫學和法律上的用語，指嚴重的精神疾病。後來英文把它借去做日常的誇飾——一個計畫、一個價錢、一場派對都可以說 insane——而今天絕大多數的用法都是後者。分清楚自己站在哪一層很重要：原本那一層是舊時代的說法，用在真實的人身上容易造成傷害，現在多改說 mentally ill；誇飾那一層則輕鬆好用，講的是「太扯了」。From the picture
Also in this word
mentally ill (dated) · adjective · C1
Having a serious, lasting illness of the mind — an old-fashioned or legal word that today is usually replaced by 'mentally ill'.
精神失常的（舊式用語）
the mentally ill (dated, collective) · adjective · C1
The insane is an old-fashioned way to mean people who are mentally ill, now usually replaced by kinder words.
精神病患（舊式集合說法）
原始詞典資料6 筆記錄
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
insaneadj/ɪnˈseɪn/
- 1
Exhibiting unsoundness or disorder of mind; not sane; utterly mad.
- What is the cause of insanity? Nobody can answer such a sweeping question as that, but we know that certain diseases, such as syphilis, break down and destroy the brain cells and result in insanity. In fact, about one-half of all mental diseases can be attributed to such physical causes as brain lesions, alcohol, toxins, and injuries. But the other half—and this is the appalling part of the story—the other half of the people who go insane apparently have nothing organically wrong with their brain cells. In post-mortem examinations, when their brain tissues are studied under the highest-powered microscopes, they are found to be apparently just as healthy as yours and mine. Why do these people go insane?
- And you told me not to drive But I made it home alive So you said that only proves that I'm insane
- 2
Used by or relating to insane people.
- an insane hospital
- an insane asylum
- 3
Causing insanity or madness.
- Were such things here, as we doe speake about? / Or haue we eaten on the insane Root, / That takes the Reason Prisoner?
- 4
informalCharacterized by excess or the utmost folly; ridiculous; impractical.
- an insane plan
- an insane amount of money
- 5
slangExtremely good; incredibly amazing.
- That guy is insane at FPS games.
- Cederstrand was all over the ice, whipping his sled around and firing pucks into the net. It's what Straschnitzki is aiming for. "He's insane. The turns, the shots. It's something I want to do some day."
- 6
informalEnraged; furious.
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。