One way to picture it: something invisible gets inside a body and does not stay there — it moves on to the next body, and the next. The picture is not just 'harm' but 'harm that spreads from one host to another'.
From the word’s history
Latin inficiō meant 'to dip in, to dye, to taint' — the image of something soaking in and changing the colour of the whole, which is why the modern word is about a thing that gets inside and alters what it enters.
拉丁文 inficiō 原意是「浸染、染色、沾污」——把東西泡進染料裡，顏色就整個變了。這個染色的畫面正好解釋現代的核心：infect 說的不是從外面打壞，而是滲進去、把裡面整個改掉，而且沾到下一個東西時同樣會把它染上。
Wiktionary: infect (from Latin infectus, participle of inficiō 'dye, taint')
登入就可以看每一支怎麼連回核心畫面。
原始詞典資料6 筆記錄
以下是外部詞典記錄的用法，摘錄並精簡格式，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。
infectverb詞源 1/ɪnˈfɛkt/
- 1
To bring (the body or part of it) into contact with a substance that causes illness (a pathogen), so that the pathogen begins to act on the body; (of a pathogen) to come into contact with (a body or body part) and begin to act on it.
- Not everyone will be infected when an epidemic strikes.
- Bats host many high-profile viruses that can infect humans, including severe acute respiratory syndrome and Ebola.
- 2
To contaminate (an object or substance) with a pathogen.
- 3
To make somebody enthusiastic about one's own passion, or to communicate a feeling to others, or a feeling communicating itself to others.
- Her passion for dancing has infected me.
- Guido, by way of diverting the embarrassment which seemed to infect them all, began to unfasten the packet of letters.
- 4
computingengineeringmathematicsOf a computer virus: to insert its own code into (another executable file).
infectadj詞源 1/ɪnˈfɛkt/
- 1
obsoleteInfected.
- And in the imitation of these twain, / Who, as Ulysses says, opinion crowns / With an imperial voice, many are infect.
infectadj詞源 2/ˈɪnfɛkt/
- 1
raregrammarhuman-scienceslinguisticsRepresenting an action not yet completed.
摘錄自 英文維基詞典 English Wiktionary，已精簡格式；依 CC BY-SA 4.0 授權使用，改動後的內容同樣以此授權提供。