hornbooks

/HH AO1 R N B UH0 K S/
noun
  1. 1

    A single page containing the alphabet, covered with a sheet of transparent horn, formerly used for teaching children to read.

  2. 2

    A legal textbook that gives a basic overview of a particular area of law.

Source: https://en.wiktionary.org/wiki/hornbook, https://en.wiktionary.org/wiki/hornbooks