The aim of compiling this dictionary is to provid descriptions of various terms of various branches of science from which the science students can extract the specific information .This dictionary includes the most commonly used terms, statements, laws and techniques .This dictionary is a veritable mine of information. An elaborate system of cross-referencing makes the dictionary easy to use and extremely informative. At few places, Diagrams have been used to illustrate the meaning of a term. Entries are compact but self-explanatory. SI units and IUPAC system of nomenclature have been used throughout this dictionaty. Students, researchers, academics and teachers will find this dictionary most useful and informative. The present dictionary will also prove to be an invaluable reference guide for the informed laymen with a professional interest in the subject. This dictionary will be useful and handy addition to your library to help you locate, Identify and expound day to day terminology in its proper context.