This reference work aims to provide a comprehensive, integrated resource for English vocabulary, spelling, and usage by combining dictionary definitions with a thesaurus. The text, overseen by lexicographer John M. Sinclair, utilizes a corpus-based approach to ensure that definitions and synonyms reflect contemporary usage. It serves as a centralized tool for writers and students seeking both clarity in meaning and variety in expression.

The subject matter points to a highly functional, utilitarian text designed for quick reference and academic support. Its integration of dictionary and thesaurus features suggests a focus on efficiency for the user, prioritizing accessibility and practical application over theoretical linguistic analysis.