400,000 entries with 10,000 new words and tenses. Full color with 4,000 photographs and illustrations. Updated guidance on usage from the renowned Usage Panel, and new notes on regionalisms and language variation and change. Revised biographical and geographical entries as well as up-to-date charts and tables for topics such as world currencies and chemical elements. Thousands of updated etymologies, a fully revised Appendix of Indo-European Roots, and a new Appendix of Semitic Roots. Thumb indexed. 8 1/2 x 11.