The Oxford English Dictionary (OED) is another popular dictionary reference book on Amazon. It is widely regarded as the most authoritative and comprehensive dictionary of the English language. The OED includes over 600,000 words, phrases, and definitions, along with their etymology and historical usage. It is a valuable resource for linguists, researchers, and anyone interested in the evolution of the English language. The OED also offers insights into the cultural and historical context of words, making it a fascinating read for language enthusiasts. With its extensive coverage and meticulous research, the Oxford English Dictionary is a top choice for those seeking a comprehensive reference book.