The Oxford English Dictionary (OED) is widely regarded as the most authoritative and comprehensive dictionary of the English language. It contains over 600,000 words, phrases, and definitions, tracing the history and usage of words from their earliest known origins to the present day. The OED is a valuable resource for linguists, researchers, and anyone interested in the evolution of the English language. It provides detailed etymologies, pronunciation guides, and usage examples, making it an essential tool for understanding the richness and complexity of English vocabulary.