This is a glossary of over 1000 terms used in Plant Pathology - the study of Plant Diseases. It covers terms in use in the current editions of the different internationally mandated and proposed books. Any abbreviations, latinizations and synonyms are incorporated, as are terms which are either no longer employed, are used outside the formal nomenclatural Codes, or are otherwise likely to be encountered. As some of the terms used in the classification of plant communities are identical to those of whole organisms, terms used in phytosociological nomenclature are also included. It is intended for use as a reference work by all biologists, especially those involved with the description or re- classification of organisms, as well as those investigating the status and application of previously proposed names.