The EGI Community is composed by a large number of heterogenous actors who contribute to providing or consuming services for e-Science. Policy makers produce policies and procedures that govern the EGI processes; dissemination experts write articles for communicating the progress and results in using or evolving EGI; end-users write papers on research results achieved through the infrastructure; technology providers report on the advancement of technology components that enable EGI to operate and so on. From many parties, it has been often expressed the need to identify a common set of terms which definition is agreed and shared so to improve the understanding and consistency of documents. The goal of the EGI Glossary is to address this problem by identifying and maintaining a shared set of terms across all the functional areas of EGI in order to enable a consistent understanding and usage within a well-defined scope.