Out like a light. Play it by ear. Off the hook. Who isn’t curious where these ­silly sayings come from? This extensive series demystifies just about every idiom a young reader can think of. Each phrase is used in a paragraph and given a definition followed by its origin story. Funny illustrations ­accompany the phrases and take up much of the page. Each page fits one or two phrases, and each book concludes with a glossary, an index, and resources for further reading. Children are also given extension activities to continue exploring idioms. VERDICT This series is a dictionary of idioms that lets kids have fun with language. ­Recommended.