The Pocket Dictionary of the Vulgar Tongue is a humorous guide to 18th-century London slang. First published in 1785, it compiles terms from the streets, taverns, and dockyards, offering a glimpse into the colorful language of the time. Originally created by a militia captain who overheard these phrases during late-night excursions, this pocket-sized dictionary reveals the origins of expressions like "birthday suit" and preserves slang forgotten by history.