to force a fluid into the body of (somebody) using a syringe
to force (a fluid) in in this way
to throw, drive, or force (something) somewhere
Fuel is injected into the engine
to introduce (something) as an element or factor
She managed to inject a lighter tone into the proceedings
injectable adj
injector noun
[Latin injectus, past part. of inicere, from in-2 + jacere to throw]