injection
gb/ɪnd͡ʒˈɛkʃən/ us/ɪnd͡ʒˈɛkʃən/
B1
English
~ 5800
Senses
0 senses
Noun
B1
action
1
putting medicine into the body
The act of using a needle to put liquid medicine into someone’s body.
Usage pattern:
give [someone] an injection of [medicine]
Common mistake:
Learners often confuse “injection” with “shot” or “jab.” All can mean the same thing in a medical context, but “shot” and “jab” are more informal. Some learners also say *“make an injection”* instead of the correct *“give an injection”* or *“have an injection.”*
Synonyms
shot (Very common in everyday speech, especially in American English; slightly more informal than “injection.”)
|
jab (Common especially in British and informal speech; often used for vaccines.)
Antonyms
oral medication (Medicine that is taken by mouth instead of being put into the body with a needle.)
Collocations
give an injection
|have an injection
|painful injection
|intravenous injection
|injection site
|injection needle
Themes
health
|medicine
|daily life
Examples
- The nurse gave me an injection to reduce the pain.
- Children often cry when they get their first injection.
- You may feel a slight sting during the injection.
- The doctor recommended a course of antibiotics by injection.
- He fainted at the sight of the injection needle.
Learner examples
- The nurse gave me an injection in my arm.
- I am scared of injections.
- You need an injection before you travel to that country.
- The doctor said this injection will help my back pain.
- She cried when she got the injection.
Noun
B1
entity
2
dose of medicine by injection
One dose of liquid medicine that a doctor or nurse puts into your body with a needle.
Usage pattern:
an injection of [medicine]
Common mistake:
Learners sometimes say *“drink an injection”* when they mean *“take medicine.”* Injections are given with a needle; medicine you drink is usually called *liquid medicine* or *syrup.*
Synonyms
dose (General term for a measured amount of medicine; does not itself imply the use of a needle.)
Antonyms
overdose (Taking too much medicine; contrasted with a single, proper injection dose.)
Collocations
an injection of insulin
|a vaccine injection
|a steroid injection
|a vitamin injection
|a flu injection
Themes
health
|medicine
Examples
- The patient received an injection of insulin before breakfast.
- My doctor recommended an injection of steroids for the joint pain.
- She goes to the clinic every month for a vitamin B12 injection.
- The travel nurse gave us a yellow fever injection.
- He refused the second injection because the first one made him feel sick.
Learner examples
- I need an injection of insulin every day.
- The doctor gave me an injection of medicine for my allergy.
- You will get one injection today and another next week.
- He goes to the hospital for a vitamin injection.
- She got a flu injection in the autumn.
Noun
B2
action
3
adding money or resources
When extra money or energy is added to a company, project, or activity to help it grow or get better.
Usage pattern:
an injection of [money/resources/energy] into [something]
Common mistake:
Learners may take this meaning literally and imagine a physical needle. In this sense, “injection” is figurative and usually refers to money, resources, or energy in business or social contexts. It is also common to forget the preposition *“of”* and say *“an injection money”* instead of *“an injection of money.”*
Synonyms
infusion (Often used in business and finance for adding money or resources; slightly more formal than “injection.”)
|
boost (More general and informal; suggests an increase or lift rather than the specific idea of adding resources from outside.)
Antonyms
withdrawal (Removal of money or support, the opposite of adding it.)
|
cutback (A reduction in money or resources, contrasted with adding more through an injection.)
Collocations
injection of capital
|injection of cash
|injection of funds
|injection of fresh blood
|injection of energy
Themes
business
|economy
|society
|finance
Examples
- The startup survived thanks to a major injection of capital from investors.
- The school needs an injection of funds to repair its buildings.
- A fresh injection of talent has transformed the team’s performance.
- The government announced an injection of cash into public transport.
- The project stalled without an injection of new ideas and energy.
Learner examples
- The company needs an injection of cash to continue.
- The club got an injection of new players this year.
- The town needs an injection of money to fix the old roads.
- The team received an injection of energy from the new coach.
- Without an injection of funds, the project will stop.
Noun
technical
B2
action
4
forcing liquid or gas into something
Putting a liquid or gas into something, often using pressure or a pump, for science or industry.
Usage pattern:
the injection of [liquid/gas] into [material/system]
Common mistake:
Learners sometimes think this technical use must be about medicine because of the medical sense. In scientific or industrial texts, “injection” often refers to fluids or gases being forced into systems, not into people.
Synonyms
pumping (Focuses on using a pump to move liquid or gas; less general and less technical than “injection.”)
Antonyms
extraction (Taking liquid or gas out of something, instead of forcing it in.)
Collocations
injection of water
|injection of steam
|injection into the reservoir
|injection pressure
|chemical injection
Themes
science
|engineering
|environment
|technology
Examples
- The process involves the injection of water into deep rock layers.
- Gas injection is used to maintain pressure in the oil reservoir.
- Accidental injection of air into the system can cause damage.
- The researchers studied the effects of chemical injection into groundwater.
- Steam injection improved the efficiency of the extraction process.
Learner examples
- The machine controls the injection of water into the tank.
- Injection of gas keeps the pressure high.
- They use injection of steam to get more oil.
- Too much injection of air can break the system.
- We tested the injection of chemicals into the soil.
Noun
technical
B2
entity
5
engine fuel delivery system
The system in an engine that puts fuel into it at the right time and in the right amount.
Usage pattern:
[type] fuel injection system
Common mistake:
Learners may think “injection” here still involves a medical-style needle. In cars and engines, it refers to a mechanical system that sprays fuel, not a medical procedure.
Synonyms
fuel delivery system (Describes the function more generally and is less specific and technical than “fuel injection.”)
Antonyms
carburetion (Older method of mixing fuel with air using a carburetor instead of an injection system.)
Collocations
fuel injection
|electronic fuel injection
|direct injection
|injection system
|injection engine
Themes
technology
|transportation
|engineering
Examples
- Modern cars use electronic fuel injection for better efficiency.
- The mechanic said there was a problem with the injection system.
- Direct injection engines can offer more power and lower emissions.
- Poor fuel injection can cause the engine to misfire.
- They upgraded the old engine to a new injection system.
Learner examples
- This car has electronic fuel injection.
- The injection system in my car is broken.
- Fuel injection helps the engine use less fuel.
- New engines with direct injection are very popular.
- The mechanic cleaned the fuel injection system.
Noun
technical
C1
action
6
malicious insertion of code
A way for attackers to put bad code or commands into a computer program or website so they can control it or get data.
Usage pattern:
[type] injection attack
Common mistake:
Learners sometimes confuse “injection” here with a physical act. In computing, it is purely about data and code, not about needles or liquids.
Synonyms
code insertion (More general and descriptive; lacks the strong technical security meaning that “injection” has.)
Antonyms
input validation (Security practice that blocks unsafe input and helps prevent injection attacks.)
Collocations
code injection
|SQL injection
|command injection
|injection attack
|injection vulnerability
Themes
technology
|computing
|security
Examples
- The website was vulnerable to SQL injection.
- Proper input validation can prevent code injection attacks.
- The report describes several types of injection vulnerabilities.
- Developers must protect APIs from injection and other common exploits.
- They used command injection to gain control of the server.
Learner examples
- The system had a problem called SQL injection.
- Code injection can let hackers run bad code.
- We must stop injection attacks on the website.
- Good input checks help prevent injection problems.
- The security team fixed the injection vulnerability.
Noun
technical
C2
relation
7
one-to-one mathematical function
In math, a function where every different input gives a different output, so no two inputs share the same output.
Usage pattern:
an injection from [set A] to [set B]
Common mistake:
Learners sometimes mix up “injection” with “surjection” or “bijection.” An injection is only about different inputs having different outputs, not about covering every element of the codomain.
Synonyms
one-to-one function (More explanatory and common in teaching; “injection” is the standard formal term in higher mathematics.)
Antonyms
many-to-one function (A function where different inputs can share the same output, the opposite property of an injection.)
Collocations
an injection from A to B
|injective injection
|bijective injection
|set-theoretic injection
Themes
mathematics
|academia
|science
|education
Examples
- The function f is an injection from R to R.
- Every bijection is, by definition, an injection and a surjection.
- We first construct an injection from set A into set B.
- If there exists an injection from A to B, then the cardinality of A is less than or equal to that of B.
- The proof relies on finding an explicit injection between the two sets.
Learner examples
- In higher math, we learn what an injection is.
- This function is an injection from set A to set B.
- If a function is an injection, no two inputs have the same output.
- They showed there is an injection from the integers to the rationals.
- Every bijection is also an injection.
Grammar
Dictionary form
injection
IPA
GB/ɪnd͡ʒˈɛkʃən/
US/ɪnd͡ʒˈɛkʃən/
Syllables & stress
in - jec - tion (3 syllables)
Stress on 2nd syllable (jec)
Word forms
Noun
- Base: injection
- Plural: injection, injections
Word family
Expressions
code injection
1/kˈoʊd ɪnd͡ʒˈɛkʃən/
fixed phrase
technical
malicious insertion of code
A way for attackers to put bad code into a program or website by abusing input fields or data channels.
Examples
- The application was vulnerable to code injection through its login form.
- Secure coding practices help protect against code injection.
fuel injection
1/fjˈul ɪnd͡ʒˈɛkʃən/
fixed phrase
technical
engine fuel delivery system
The system in a car or other engine that sprays fuel into it instead of using a carburetor.
Examples
- Modern motorcycles usually have fuel injection instead of carburetors.
- Fuel injection can improve both power and fuel economy.
give someone an injection
1/ɡˈɪv sˈʌmwˌʌn ən ɪnd͡ʒˈɛkʃən/
fixed phrase
to administer an injection
To put medicine into a person or animal using a needle and syringe.
Examples
- The nurse will give you an injection before the operation.
- The vet gave the dog an injection to calm it down.
have an injection
1/hˈæv ən ɪnd͡ʒˈɛkʃən/
fixed phrase
to receive an injection
To get medicine put into your body with a needle and syringe.
Examples
- I have to have an injection before I travel.
- He had an injection for tetanus after the accident.
injection molding
1/ɪnd͡ʒˈɛkʃən mˈoʊldɪŋ/
fixed phrase
technical
manufacturing by forcing material into a mold
A factory process where hot, melted plastic or metal is pushed into a mold to make a shape.
Examples
- Most of these plastic parts are made using injection molding.
- Injection molding allows for fast, high-volume production.
injection of capital
1/ɪnd͡ʒˈɛkʃən əv kˈæpɪtəl/
fixed phrase
adding investment money
New money that is put into a business or project to help it grow or survive.
Examples
- The company needed an injection of capital to avoid bankruptcy.
- A large injection of capital allowed the startup to expand overseas.
injection of cash
1/ɪnd͡ʒˈɛkʃən əv kˈæʃ/
fixed phrase
adding a sum of money
Extra money that is added to help an activity, group, or system continue or improve.
Examples
- The charity received an urgent injection of cash from private donors.
- The festival was saved by a last-minute injection of cash.
SQL injection
1/ˈɛs kjˈu ˈɛl ɪnd͡ʒˈɛkʃən/
fixed phrase
technical
database query attack
A hacker attack where bad SQL commands are added to a website’s or app’s database query through user input.
Examples
- The team fixed a serious SQL injection vulnerability in the login page.
- Poorly validated form fields can lead to SQL injection attacks.