Create a Domain Model
Requirements analysis will reveal a number of business terms that must be defined if the requirements are to be understood and clarified. There are a number of options for recording these terms, including the Project Glossary, which is a purpose built lexicon through which you can list, define and categorize terms. The Domain Model (business object model) is another powerful mechanism for describing the important terms of the business, providing a single definition of the terms and their relationships that is accessible to all project staff, from high level business managers to low level engineers. One of the advantages of using a Domain Model is that the terms are modeled as elements, allowing them to be linked to other elements within the Domain Model itself or to elements in other parts of the models.
Enterprise Architect has extensive support for modeling a domain using a UML Class diagram, or the Classes can be created directly in the Browser window and displayed in a list using the Package List window.
The Domain Model elements can be added to other diagrams to make them more expressive and to show important information, such as what data is being consumed or produced by a business process, or what data is being passed between application interfaces.
Enterprise Architect allows you to link to the domain elements (or any element) from the text of a requirement's notes. (This facility is available from any element.)
Experienced modelers tend to define the terms of a domain in a Domain Model and reserve the Glossary for project and process terms and their definitions such as Use Case, Software Requirements Specification, Metric etc.