This dictionary includes some 9,200 terms, each with a definition and often and additional descriptive text in English, the terms being translated in French, German and Spanish. It is more complete than similar previously published dictionaries or glossaries, and contains all fields of soil science as well as some adjacent fields of other earth sciences, agriculture and engineering. Present concepts and definitions are detailed along with earlier concepts, not only for historical reasons but also for developing new ideas. Concepts, terms and definitions usual in literature of various countries are discussed and compared, to offer an appropriate exchange of ideas. Soil classifications and methodologies for soil investigation coming from a score of European, American and other countries and international organisations are presented, and correlations between names of soil taxa in different classifications are suggested.