HORNBOOK
hornbook
(noun) a primer that provides instruction in the rudiments or basic skills of a branch of knowledge
Source: WordNet® 3.1
Etymology
Noun
hornbook (plural hornbooks)
A single page containing the alphabet, covered with a sheet of transparent horn, formerly used for teaching children to read.
(legal) A legal textbook that gives a basic overview of a particular area of law.
Source: Wiktionary
Horn"book`, n.
1. The first book for children, or that from which in former times
they learned their letters and rudiments; -- so called because a
sheet of horn covered the small, thin board of oak, or the slip of
paper, on which the alphabet, digits, and often the Lord's Prayer,
were written or printed; a primer. "He teaches boys the hornbook."
Shak.
2. A book containing the rudiments of any science or branch of
knowledge; a manual; a handbook.
Source: Webster’s Unabridged Dictionary 1913 Edition