- The container holding the electrolyte and plates in a storage cell.
- An older unit of capacitance equal to approximately 1.11 × 10-9 farad, which is the approximate capacitance of a Leyden jar.
- noun a pint of beer. A pub habitués’ term which has been in widespread use since the 1950s. At the turn of the 20th century ale was served in china mugs, known as jars, as well as glasses.
- noun a pot, usually glass, for keeping food in
- acronym forJoint Aviation Requirements (written as JAR)