An inject is when liquid medicine or substance goes into your body through a small needle.
The word "inject" is used every day in hospitals and medical offices. Imagine going to the doctor for a flu shot - that's an example of being injected with a vaccine to help keep you healthy. When people have allergies, they might need an EpiPen, which injects medicine into their skin to stop severe reactions. Medical professionals also use injections to give patients pain relief or other medications directly into their veins through a small needle.
How common is "inject"?
Word inject is considered uncommon in modern English. It has a balanced usage among all categories: speech, fiction, newspapers and academic texts.
Definitions
verb
(transitive) To push or pump (something, especially fluids) into a cavity or passage.
Example: The nurse injected a painkilling drug into the veins of my forearm.
(transitive) To introduce (something) suddenly or violently.
Example: Punk injected a much-needed sense of urgency into the British music scene.
(transitive) To administer an injection to (someone or something), especially of medicine or drugs.
Example: Now lie back while we inject you with the anesthetic.
(intransitive) To take or be administered something by means of injection, especially medicine or drugs.
Example: It's been a week since I stopped injecting, and I'm still in withdrawal.
(transitive, computing) To introduce (code) into an existing program or its memory space, often without tight integration and sometimes through a security vulnerability.
(obsolete, transitive) To cast or throw; used with on.
(transitive) To introduce or add (something that is different or foreign).