jar1
  
  n.
  - a wide-mouthed cylindrical container made of glass or pottery.
- Brit. informal a glass of beer.
Etymology
  C16: from Fr. jarre, from Arab. jarra.
 
  
    
jar2
  
  v.
 (jars, jarring, jarred)
  - send a painful or uncomfortable shock through (a part of the body). ▸strike against something with an unpleasant vibration or jolt. 
- have a disturbing or incongruous effect.
n.
 an instance of jarring.
Derivative
  
    - jarring adj.
- jarringly adv.
 
  Etymology
  C15 (as a noun in the sense ‘disagreement, dispute’): prob. imitative.
 
  
    
jar3
  
  n.
 
(
in phr. on the jar)
 
informal or 
dialect ajar.
Etymology
  C17: later form of obs. char ‘turn’ (see also ajar and charwoman).