definition

jar [ jahr ] / dʒɑr /

A wide-mouthed container that is usually cylindrical, made of glass or earthenware, and without handles.
Also: jarful the contents or quantity contained in a jar.
British informal; a glass of alcoholic drink, esp beer: to have a jar with someone.
(obsolete) a measure of electrical capacitance.
On a jar or on the jar (of a door) slightly open; ajar.
A jolt or shake; a vibrating movement, as from concussion.
A sudden unpleasant effect upon the mind or feelings; shock.
A harsh, grating, discordant sound or combination of sounds.
A quarrel or disagreement, especially a minor one.
(Archaic) a turn or turning.

To have a harshly unpleasant or perturbing effect on one's nerves, feelings, thoughts, etc.: The sound of the alarm jarred.
To produce a harsh, grating sound; sound discordantly.
To vibrate, rattle, or shake.
To conflict, clash, or disagree.