Source : Webster's Revised Unabridged Dictionary (1913)

Grammar \Gram"mar\, n. [OE. gramere, OF. gramaire, F. grammaire
   Prob. fr. L. gramatica Gr ?, fem. of ? skilled in grammar,
   fr. ? letter. See {Gramme}, {Graphic}, and cf. {Grammatical},
   {Gramarye}.]
   1. The science which treats of the principles of language;
      the study of forms of speech, and their relations to one
      another; the art concerned with the right use aud
      application of the rules of a language, in speaking or
      writing.

   Note: The whole fabric of grammar rests upon the classifying
         of words according to their function in the sentence.
         --Bain.

   2. The art of speaking or writing with correctness or
      according to established usage; speech considered with
      regard to the rules of a grammar.

            The original bad grammar and bad spelling.
                                                  --Macaulay.

   3. A treatise on the principles of language; a book
      containing the principles and rules for correctness in
      speaking or writing.

   4. treatise on the elements or principles of any science; as,
      a grammar of geography.

   {Comparative grammar}, the science which determines the
      relations of kindred languages by examining and comparing
      their grammatical forms.

   {Grammar school}.
      (a) A school, usually endowed, in which Latin and Greek
          grammar are taught, as also other studies preparatory
          to colleges or universities; as, the famous Rugby
          Grammar School. This use of the word is more common in
          England than in the United States.

                When any town shall increase to the number of a
                hundred families or householders, they shall set
                up a grammar school, the master thereof being
                able to instruct youth so far as they may be
                fitted for the University.        --Mass.
                                                  Records
                                                  (1647).
      (b) In the American system of graded common schools an
          intermediate grade between the primary school and the
          high school, in which the principles of English
          grammar are taught.