Designing a terminological knowledge base consists in collecting terms and associating them to their definition. Our objective is to define a process model to support this design task in a collaborative work environment. The proposed concept model is based on terminological logic and the issue-based model IBIS. The terminological logic part is intended to formally express definitions and associate them to terms and points of view. The process model we define is based on a cyclic conflict resolution process. It includes a formal concept comparison operation, to highlight definition conflicts and their nature, and other operations (derivation, intersection, union, etc.) to solve the detected conflicts. The IBIS part of the model enable users to express and record issues, positions, arguments and endorsements that occur during conflict resolution.