to target; to focus on; to be aimed at or against; in response to

tip of a needle; syringe needle

syringe

pinhole

to oppose each other with equal harshness (idiom); tit for tat; measure for measure

to give or get an injection

compass

brooch

pin; safety pin; clip; brooch; CL:枚[mei2]

pointer on a gauge; clock hand; cursor; (computing) pointer