1911 Encyclopædia Britannica/Jargon
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.