Source : Webster's Revised Unabridged Dictionary (1913)

Schoolbook \School"book`\, n.
   A book used in schools for learning lessons.

Source : WordNet®

schoolbook
     n : a book prepared for use in schools or colleges; "his
         economics textbook is in its tenth edition"; "the
         professor wrote the text that he assigned students to
         buy" [syn: {textbook}, {text}, {text edition}, {school
         text}] [ant: {trade book}]