人從一方脫離
同一個「脫落」用在人身上：本來屬於這個國家、這支隊伍、這個政黨，後來離開，加入了另一邊。
switch sides/defect · verb · C1
To leave your own country, team, or group and join a different, often opposing, one.
叛逃；投奔（到另一方）
核心畫面
One way to hold it: something that should be there has fallen away. In a product, a piece is missing or wrong, so it does not work as it should. In a person's loyalty, the same falling-away happens — they were on this side, and now they are not. The two uses look unrelated, but they are the same word doing the same thing to different objects.
可以想成本來該在的東西掉了：在產品上，是少了一塊或做壞了，所以不能正常運作；在忠誠上，是一個人原本站這一邊，後來不站…更多收起
可以想成本來該在的東西掉了：在產品上，是少了一塊或做壞了，所以不能正常運作；在忠誠上，是一個人原本站這一邊，後來不站了。名詞的「瑕疵」和動詞的「叛逃」看起來八竿子打不著，其實是同一個字，只是「脫落」發生在不同的東西上。From the word’s history
Both are from Latin defectus, past participle of deficere "to fail, desert" (de- "down, away" + facere "to do, make"). The noun (early 15c.) first meant "want or lack of anything"; the verb "to desert, revolt" appears in the 1590s — Latin deficere already carried both the "falling short" and the "falling away" readings.
兩個意思同源，都來自拉丁語 defectus（deficere「失敗、背離」的過去分詞，de-「向下、離開」＋ facere「做」）。名詞在十五世紀初的意思是「缺少、不足」，動詞「叛離」則出現在 1590 年代——拉丁語的 deficere 本來就同時帶有「不足」和「脫離」兩種讀法。
Etymonline (etymonline.com/word/defect)
From the picture
Also in this word
fault/flaw · noun · C1
A fault or a missing part that keeps something or someone from being perfect.
缺陷；瑕疵
原始詞典資料7 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。
defectnoun/ˈdiːfɛkt/
- 1
A fault or malfunction.
- a defect in the ear or eye; a defect in timber or iron; a defect of memory or judgment
- Among boys little tenderness is shown to personal defects.
- 2
The quantity or amount by which anything falls short.
- and the indefatigable application with which they have supplied the defects of early culture.
- 3
mathematicssciencesA part by which a figure or quantity is wanting or deficient.
defectverb/dɪˈfɛkt/
- 1
To abandon or turn against; to cease or change one's loyalty, especially from a military organisation or political party.
- Capitalizing on the restive mood, Mr. Farage, the U.K. Independence Party leader, took out an advertisement in The Daily Telegraph this week inviting unhappy Tories to defect. In it Mr. Farage sniped that the Cameron government — made up disproportionately of career politicians who graduated from Eton and Oxbridge — was “run by a bunch of college kids, none of whom have ever had a proper job in their lives.”
- 2
governmentmilitarypoliticsTo desert one's army, to flee from combat.
- 3
governmentmilitarypoliticsTo join the enemy army.
- 4
lawTo flee one's country and seek asylum.
- Passing through Thailand, she submitted a handwritten statement agreeing to defect, a requirement for North Korean refugees to be allowed to enter the South.
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。