schoolbook
A book used in school to teach a subject.
A schoolbook is a textbook or other book used for studying in school. When teachers assign reading from a schoolbook, they're asking students to learn from books specifically written to teach subjects like mathematics, history, science, or literature.
Schoolbooks are different from books you might choose to read for fun. They're designed to explain concepts step by step, with practice problems, review questions, and clear explanations. A math schoolbook might show how to solve equations, while a history schoolbook presents important events in an organized way.
The word can also describe something very typical or conventional, like it came straight from a textbook. If someone makes a schoolbook tackle in football, they executed it exactly the way coaches teach. A schoolbook example of honesty might be returning a lost wallet to its owner. When something is called schoolbook, it means it's a perfect, classic illustration of how things should be done, as if you could find it as an example in an actual schoolbook.