Definition of "Jab" :

noun: the act of touching someone suddenly with your finger or elbow

noun: a quick short straight punch

noun: a sharp hand gesture (resembling a blow)

"He warned me with a jab with his finger."

verb: poke or thrust abruptly

"He jabbed his finger into her ribs."

verb: stab or pierce

"He jabbed the piece of meat with his pocket knife."

verb: strike or punch with quick and short blows