- a sheet of parchment with the alphabet, a table of numbers, etc. on it, mounted on a small board with a handle and protected by a thin, transparent plate of horn: it was formerly used as a child's primer
- an elementary treatise
- An early primer consisting of a single page protected by a transparent sheet of horn, formerly used in teaching children to read.
- A text that instructs in the basic skills or rudiments of a subject.
hornbook - Legal Definition
A law textbook, often one relied upon as authoritative in the field.