實體推送：藥與液體
這一支是核心畫面本身的字面實現——真的有液體被加壓送進一個封閉的體內。
medical injection · noun · C2
The act of putting medicine into a person's body with a special needle.
注射
核心畫面
One way to picture it: something is pushed in from outside, through a narrow opening, into a body that is already closed and working. The stuff goes to the inside — where it takes effect — and it gets there by force, not by being poured or invited in.
有個東西被從外面「推進去」——穿過一個很小的入口，進到一個本來封起來、而且正在運轉的體內。三個要素都重要：一是由外而…更多收起
有個東西被從外面「推進去」——穿過一個很小的入口，進到一個本來封起來、而且正在運轉的體內。三個要素都重要：一是由外而內，二是靠壓力送進去（不是慢慢倒、不是自己流進去），三是進去以後會在裡面起作用。針筒推進手臂是這個畫面最直接的樣子，而只要你保留「從外面加壓推入一個運轉中的系統」這個骨架，錢和燃油的用法就都跟著站起來了。From the word’s history
From Middle French injection, from Latin iniectio, from in- 'in' + iacere 'to throw' — literally 'a throwing in'. The Latin picture of throwing something in is still exactly what all three modern senses do.
injection 來自中古法語 injection、拉丁語 iniectio，拆開是 in-（進去）+ iacere（丟、投擲），字面就是「往裡面丟進去」。這個「投入」的動作感一直留到今天：不管丟進去的是藥、是錢還是燃油，都是從外面用力送進一個已經在那裡的容器或系統。（數學上的 injection「單射」是另一條路：由 Bourbaki 在 Éléments de mathématique 中引進的專門術語，不在本詞條的三個意思裡。）
Wiktionary (injection, noun etymology: Middle French injection < Latin iniectio; math sense coined in Bourbaki's Éléments de mathématique)
Two branches
比喻推送：把資金打進去
把「打針救命」整個畫面搬到組織上：公司被當成一個正在衰弱的身體，錢就是那一針。
cash injection · noun · C2
A large amount of money put into a business, project, or group so that it can get better or keep going.
注資
原始詞典資料14 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。
injectionnoun/ɪnˈd͡ʒɛk.ʃən/
- 1
The act of injecting, or something that is injected.
- For some indications in PET imaging, it is necessary for radiopharmaceutical injections to be administered contralaterally or pedally to the disease process
- 2
A specimen prepared by injection.
- 3
category-theorycomputingengineeringA morphism from either one of the two components of a coproduct to that coproduct.
- 4
businessconstructionmanufacturingThe act of inserting materials like concrete grout or gravel by using high pressure pumps.
- 5
The supply of additional funding to a person or a business.
- The troubled business received a much-needed cash injection.
- 6
mathematicssciencesA relation on sets (X,Y) that associates each element of Y with at most one element of X.
- 7
The insertion of program code into an application, URL, hardware, etc.; especially when malicious or when the target is not designed for such insertion.
- a SQL injection exploit allowing a malicious user to modify a database query
- 8
aerospacebusinessengineeringThe act of putting a spacecraft into a particular orbit, especially for changing a stable orbit into a transfer orbit, e.g. trans-lunar injection.
- It had been determined that one of the whip turnstile antennas had broken off from Explorer 1 shortly after injection into orbit, so these were eliminated.
另外 6 個記錄的用法
- 9
mathematicssciencesset-theoryA function that maps distinct x in the domain to distinct y in the codomain; formally, a f: X → Y such that f(a) = f(b) implies a = b for any a, b in the domain.
- 10
medicinesciencesSomething injected subcutaneously, intravenously, or intramuscularly by use of a syringe and a needle.
- 11
medicinesciencesCongestion (of a body part, with blood or other fluid), such as hyperemia.
- conjunctival injection
- 12
Fuel injection: the pressurized introduction of fuel into a cylinder.
- direct injection
- tuned port injection
- 13
The act of throwing cold water into a condenser to produce a vacuum.
- 14
The cold water thrown into a condenser to produce a vacuum.
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。