Medicine injector (7)
I believe the answer is:
syringe
'medicine injector' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for syringe that I've seen before include "It injects or extracts fluids" , "one's prepared for a shot" , "A jab is administered through this" , "Injector" , "Means of injection" .)