Webster's English Dictionary

dialect

di.a.lect \'di--*-.lekt\ \.di--*-'lek-t*l\ \-t*l-e-\ n [MF dialecte, fr. L 
   dialectus, fr. Gk dialektos conversation,] often attrib  dialect, fr. 
   dialegesthai to converse 1a: a regional variety of language distinguished 
   by features of vocabulary,  grammar, and pronunciation from other regional 
   varieties and constituting together with them a single language {the Doric 
   ~ of ancient Greek} 1b: one of two or more cognate languages {French and 
   Italian are Romance  ~s} 1c: a regional variety of a language usu. 
   transmitted orally and differing  distinctively from the standard language 
   {the Lancashire ~ of English} 1d: a variety of a language used by the 
   members of an occupational group (the ~ of the atomic physicist} 1e: the 
   customary language of a social class {peasant ~}  2: manner or means of 
   expressing oneself : PHRASEOLOGYM, ARGOT, SLANG mean a form of language 
   that is not recognized as standard. DIALECT applies commonly to a form of 
   language persisting regionally or among the uneducated; VERNACULAR applies 
   to the everyday speech of the people in contrast to that of learned men; 
   LINGO is a mildly contemptuous term for any language not readily 
   understood; JARGON applies to a technical or esoteric language used by a 
   profession, trade, or cult; it may also be a stronger designation than 
   LINGO for language or usage that sounds outlandish; CANT is applied 
   derogatorily to language that is both peculiar to a group or class and 
   intrinsically lacking in clarity or precision of expression {journalistic 
   cant}; ARGOT is applied to a peculiar language of a clique or other closely 
   knit group {thieves' argot}; SLANG designates a class of mostly recently 
   coined and frequently short-lived terms or usages informally preferred to 
   standard language as being forceful, novel, or voguish - di.a.lec.tal aj 
   SYN syn DIALECT, VERNACULAR, LINGO, JARGON, CANT)