jab (n.) Look up jab at Dictionary.com
1825, "a thrust or poke with the point of something," from jab (v.). Meaning "a punch with the fist" is from 1889. Sense of "injection with a hypodermic needle," once beloved by newspaper headline writers, is from 1914.
jab (v.) Look up jab at Dictionary.com
1813, "to thrust or strike with a point," a Scottish variant of job "to strike, pierce, thrust," from Middle English jobben "to jab, thrust, peck" (c. 1500), a word of unknown origin, perhaps imitative. Related: Jabbed; jabbing.