jargon Look up jargon at Dictionary.com
mid-14c., "unintelligible talk, gibberish," from O.Fr. jargon "a chattering" (of birds), ultimately of echoic origin (cf. L. garrire "to chatter," Eng. gargle). Often applied to something the speaker does not understand, hence meaning "mode of speech full of unfamiliar terms" (1650s).