This reference work investigates the evolution and usage of slang across seven centuries of the English language. Author Rosalind Fergusson compiles approximately 5,000 entries to provide a comprehensive overview of informal speech patterns. The text utilizes historical dating and geographical context to explain how specific terms emerged and integrated into common parlance. By documenting expressions from the 14th century to the late 20th century, the book establishes a framework for understanding the social and cultural shifts reflected in colloquial vocabulary.

Experts and word enthusiasts frequently cite this dictionary as a useful tool for tracking the development of informal English. Readers often note the accessibility of the definitions and the utility of the provided usage examples for historical and linguistic research.