The Synonymous Dictionary for MSDict Viewer contains 20,224 words and 57,631 different meanings presented in rich-text format. For each dictionary article, in addition to the headword meaning and its synonyms, are provided cross references and similar words. The key features of the English Synonymous Dictionary: clear and concise word definitions; typical patterns illustrating the usage; multiple senses presented; hyperlinks between the related words in the dictionary; guidance on grammar and style; examples of usage. The English Synonymous Dictionary is utilized by MSDict Viewer - an innovative dictionary reader specially designed to combine high data compression for memory restricted devices with a fast search algorithm, and user-friendly interface with amazing speed. The viewer supports multiple dictionaries installed at a time. Version 4.0 was optimized to support the new English Synonymous Dictionary.