Source : Webster's Revised Unabridged Dictionary (1913)

Alphabet \Al"pha*bet\, n. [L. alphabetum, fr. Gr. ? + ?, the
   first two Greek letters; Heb. [=a]leph and beth: cf. F.
   alphabet.]
   1. The letters of a language arranged in the customary order;
      the series of letters or signs which form the elements of
      written language.

   2. The simplest rudiments; elements.

            The very alphabet of our law.         --Macaulay.

   {Deaf and dumb alphabet}. See {Dactylology}.

Alphabet \Al"pha*bet\, v. t.
   To designate by the letters of the alphabet; to arrange
   alphabetically. [R.]

Source : WordNet®

alphabet
     n 1: a character set that includes letters and is used to write a
          language
     2: the elementary stages of any subject (usually plural); "he
        mastered only the rudiments of geometry" [syn: {rudiment},
         {first rudiment}, {first principle}, {ABC}, {ABC's}, {ABCs}]