Dialect

noun

1. A variety of a language that is characteristic of a particular area, community or social group, differing from other varieties of the same language in relatively minor ways as regards grammar, phonology, and lexicon.
2. Language that is perceived as substandard or wrong.
3. A language existing only in an oral or non-standardized form, especially a language spoken in a developing country or an isolated region.
4. A lect (often a regional or minority language) as part of a group or family of languages, especially if they are viewed as a single language, or if contrasted with a standardized idiom that is considered the 'true' form of the language (for example, Cantonese as contrasted with Mandarin Chinese, or Bavarian as contrasted with Standard German).
5. A variant of a non-standardized programming language.

   "Home computers in the 1980s had many incompatible dialects of BASIC."