What is the meaning of Jab?

A quick stab or blow; a poking or thrusting motion.

A short straight punch.

A medical hypodermic injection (vaccination or inoculation)

A vaccination, whether or not delivered via conventional injection.

A mild verbal insult.

To poke or thrust abruptly, or to make such a motion.

To deliver a quick punch.

To give someone an injection.

To vaccinate or inoculate someone.

job, piece of work

post, employment

jab (boxing punch)

full of, fully

not ... the

direction

jab

Source: wiktionary.org