Dictionary of the Illegible explores the limits of language—its beginnings and its ends—from humanity’s earliest marks to the dissolution of modern alphabets before our eyes. Mapping more than 400 examples of illegibility drawn from Indigenous cultures to imagined future civilizations, the book spans contemporary art, science fiction, politics, architecture, and technology. Dictionary of the Illegible proposes illegibility as a strategy for navigating a world increasingly governed by visibility, efficiency, and total surveillance.