JAR, a vessel of simple form, made of earthenware, glass, &c., with a spoutless mouth, and usually without handles. The word came into English through Fr. _jarre_ or Span, _jarra_, from Arab, _jarrah_, the earthenware vessel of Eastern countries, used to contain water, oil, wine, &c. The simple electrical condenser known as a _Leyden Jar_ (q.v.) was so called because of the early experiments made in the science of electricity at Leiden. In the sense of a harsh vibrating sound, a sudden shock or vibrating movement, hence dissension, quarrel or petty strife, "jar" is onomatopoeic in origin; it is also seen in the name of the bird night-jar (also known as the goat-sucker). In the expression "on the jar" or "ajar," of a door or window partly open, the word is another form of _chare_ or _char_, meaning turn or turning, which survives in charwoman, one who works at a turn, a job and _chore_, a job, spell of work. JARGON, in its earliest use a term applied to the chirping and twittering of birds, but since the 15th century mainly confined to any language, spoken or written, which is either unintelligible to the user or to the hearer. It is particularly applied by uninstructed hearers or readers to the language full of technical terminology used by scientific, philosophic and other writers. The word is O. Fr., and Cotgrave defines it as "gibridge (gibberish), fustian language." It is cognate with Span. _gerigonza_, and Ital. _gergo_, _gergone_, and probably related to the onomatopoeic O. Fr. _jargouiller_, to chatter. The root is probably seen in Lat. _garrire_, to chatter.