jar

Concise Oxford English Dictionary © 2008 Oxford University Press:
jar1

▶noun

• 1 a wide-mouthed cylindrical container made of glass or pottery.

• 2 Brit. informal a glass of beer.

– origin C16: from Fr. jarre, from Arab. jarra.

Concise Oxford English Dictionary © 2008 Oxford University Press:
jar2

▶verb (jars, jarring, jarred)

• 1 send a painful or uncomfortable shock through (a part of the body).

  ■ strike against something with an unpleasant vibration or jolt.

• 2 have a disturbing or incongruous effect.

▶noun an instance of jarring.

– derivatives
jarring adjective,
jarringly adverb.

– origin C15 (as a noun in the sense ‘disagreement, dispute’): prob. imitative.

Concise Oxford English Dictionary © 2008 Oxford University Press:
jar3

▶noun (in phr. on the jar) informal or dialect ajar.

– origin C17: later form of obs. char ‘turn’ (see also ajar and charwoman).