\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.