The Collaborative International Dictionary of English v.0.48:

Language \Lan"guage\, n. [OE. langage, F. langage, fr. L. lingua
   the tongue, hence speech, language; akin to E. tongue. See
   Tongue, cf. Lingual.]
   [1913 Webster]
   1. Any means of conveying or communicating ideas;
      specifically, human speech; the expression of ideas by the
      voice; sounds, expressive of thought, articulated by the
      organs of the throat and mouth.
      [1913 Webster]

   Note: Language consists in the oral utterance of sounds which
         usage has made the representatives of ideas. When two
         or more persons customarily annex the same sounds to
         the same ideas, the expression of these sounds by one
         person communicates his ideas to another. This is the
         primary sense of language, the use of which is to
         communicate the thoughts of one person to another
         through the organs of hearing. Articulate sounds are
         represented to the eye by letters, marks, or
         characters, which form words.
         [1913 Webster]

   2. The expression of ideas by writing, or any other
      instrumentality.
      [1913 Webster]

   3. The forms of speech, or the methods of expressing ideas,
      peculiar to a particular nation.
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   4. The characteristic mode of arranging words, peculiar to an
      individual speaker or writer; manner of expression; style.
      [1913 Webster]

            Others for language all their care express. --Pope.
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   5. The inarticulate sounds by which animals inferior to man
      express their feelings or their wants.
      [1913 Webster]

   6. The suggestion, by objects, actions, or conditions, of
      ideas associated therewith; as, the language of flowers.
      [1913 Webster]

            There was . . . language in their very gesture.
                                                  --Shak.
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   7. The vocabulary and phraseology belonging to an art or
      department of knowledge; as, medical language; the
      language of chemistry or theology.
      [1913 Webster]

   8. A race, as distinguished by its speech. [R.]
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            All the people, the nations, and the languages, fell
            down and worshiped the golden image.  --Dan. iii. 7.
      [1913 Webster]

   9. Any system of symbols created for the purpose of
      communicating ideas, emotions, commands, etc., between
      sentient agents.
      [PJC]

   10. Specifically: (computers) Any set of symbols and the
       rules for combining them which are used to specify to a
       computer the actions that it is to take; also referred to
       as a computer lanugage or programming language; as,
       JAVA is a new and flexible high-level language which has
       achieved popularity very rapidly.
       [PJC]

   Note: Computer languages are classed a low-level if each
         instruction specifies only one operation of the
         computer, or high-level if each instruction may specify
         a complex combination of operations. Machine language
         and assembly language are low-level computer
         languages. FORTRAN, COBOL and C are high-level
         computer languages. Other computer languages, such as
         JAVA, allow even more complex combinations of low-level
         operations to be performed with a single command. Many
         programs, such as databases, are supplied with special
         languages adapted to manipulate the objects of concern
         for that specific program. These are also high-level
         languages.
         [PJC]

   Language master, a teacher of languages. [Obs.]

   Syn: Speech; tongue; idiom; dialect; phraseology; diction;
        discourse; conversation; talk.

   Usage: Language, Speech, Tongue, Idiom, Dialect.
          Language is generic, denoting, in its most extended
          use, any mode of conveying ideas; speech is the
          language of articulate sounds; tongue is the
          Anglo-Saxon term for language, esp. for spoken
          language; as, the English tongue. Idiom denotes the
          forms of construction peculiar to a particular
          language; dialects are varieties of expression which
          spring up in different parts of a country among people
          speaking substantially the same language.
          [1913 Webster]

WordNet (r) 3.0 (2006):

programming language
    n 1: (computer science) a language designed for programming
         computers [syn: programming language, programing
         language]

The Free On-line Dictionary of Computing (30 December 2018):

programming language
computer language

    A formal language in which computer programs are
   written.  The definition of a particular language consists of both
   syntax (how the various symbols of the language may be combined)
   and semantics (the meaning of the language constructs).

   Languages are classified as low level if they are close to
   machine code and high level if each language statement
   corresponds to many machine code instructions (though this
   could also apply to a low level language with extensive use of
   macros, in which case it would be debatable whether it still
   counted as low level).  A roughly parallel classification is
   the description as first generation language through to
   fifth generation language.

   The other major classification of languages distinguishes
   between imperative languages, procedural language and
   declarative languages.

   Programming languages in this dictionary
   (/contents/language.html).

   Programming languages time-line/family tree
   (http://levenez.com/lang/history.html).

   (2004-05-17)