Chambers's Twentieth Century Dictionary (Part 1 of 4: A-D) is the opening volume of a comprehensive reference work covering words beginning with the letters A through D. Compiled under the name of Thomas Davidson, this dictionary provides definitions, explanations, and linguistic information that reflect the vocabulary and language usage of its period.

Designed as a practical reference for readers, students, writers, and language enthusiasts, the volume offers a valuable resource for exploring word meanings, spelling, and the development of English vocabulary. It also provides historical insight into early twentieth-century lexicography and the traditions of English dictionary-making.