1. a book or set of books containing articles on many topics, usually arranged alphabetically; an encyclopedia.
Usage: chiefly British spelling; American English typically uses 'encyclopedia'; often used in titles of reference works

Examples

• She consulted the cyclopaedia to find information about ancient Rome.
• The library's cyclopaedia was a valuable resource for students writing research papers.
• A cyclopaedia of music history covered composers from the Renaissance to the modern era.
• The cyclopaedia contained thousands of entries on science, art, and literature.
• Before the internet, families often kept a cyclopaedia on their shelves for quick reference.