Jar2  —v. (-rr-) 1 (often foll. By on) (of sound, manner, etc.) Sound discordant, grate (on the nerves etc.). 2 a (often foll. By against, on) (cause to) strike (esp. Part of the body) with vibration or shock (jarred his neck). B vibrate with shock etc. 3 (often foll. By with) be at variance or in conflict. —n. 1 jarring sound or sensation. 2 physical shock or jolt. [imitative]