Source : Webster's Revised Unabridged Dictionary (1913)

Abecedarian \A`be*ce*da"ri*an\, n. [L. abecedarius. A word from
   the first four letters of the alphabet.]
   1. One who is learning the alphabet; hence, a tyro.

   2. One engaged in teaching the alphabet. --Wood.

Abecedarian \A`be*ce*da"ri*an\, Abecedary \A`be*ce"da*ry\, a.
   Pertaining to, or formed by, the letters of the alphabet;
   alphabetic; hence, rudimentary.

   {Abecedarian psalms}, {hymns}, etc., compositions in which
      (like the 119th psalm in Hebrew) distinct portions or
      verses commence with successive letters of the alphabet.
      --Hook.

Source : WordNet®

abecedarian
     adj : alphabetically arranged (as for beginning readers)
     n 1: a novice learning the rudiments of some subject
     2: a 16th century sect of Anabaptists centered in Germany who
        had an absolute disdain for human knowledge