Vaccination, informally (3)
I believe the answer is:
jab
(Other definitions for jab that I've seen before include "A short stiff punch" , "Short straight punch" , "Short stiff blow or thrust" , "Poke roughly or inject" , "Prod" .)
I believe the answer is:
jab
(Other definitions for jab that I've seen before include "A short stiff punch" , "Short straight punch" , "Short stiff blow or thrust" , "Poke roughly or inject" , "Prod" .)