sublanguage

/ˈsʌbˌlæŋɡwɪdʒ/
noun
  1. A specialized or limited form of a language used by a particular group, profession, or for a specific purpose.
    • In legal documents, the sublanguage includes many Latin phrases that confuse non-lawyers.
    • The programming sublanguage used by database administrators is different from everyday English.
    • Medical professionals use a sublanguage full of terms like 'myocardial infarction' instead of 'heart attack'.