What is "abecedary"

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.

Abecedary \A`be*ce"da*ry\, n. A primer; the first principle or rudiment of anything. [R.]
--Fuller.

"primer, alphabet table," mid-15c., from Medieval Latin abecedarium "an ABC book," neuter of adjective abecedarius, used as a noun, from the first four letters of the Latin alphabet. Abecedarian (adj.) is attested from 1660s.

a. Referring to the alphabet; alphabetical; related to or resembling an abecedarius; abecedarian. (First attested from 1350 to 1470.) n. 1 (context rare English) The alphabet, written out in a teaching book, or carved on a wall; a primer; abecedarium. (First attested from 1350 to 1470.) 2 One that teaches or learns the alphabet or the fundamentals of any subject; abecedarian. (Late 16^th century.)