This report explores the growing importance of citizen science and the critical need for clear, accessible communication of scientific concepts to non-experts. As citizen involvement in research increases, so does the need to ensure that terminology is not a barrier to participation. One key challenge is the development and use of simplified definitions that are understandable to a general audience without compromising scientific accuracy. To address this, the report proposes a structured methodology for the comprehension based appraisal of definitions by non-experts. This collaborative yet controlled process enables the evaluation of whether simplified terms truly support inclusive engagement. Central to this approach is the role of the terminologist, who acts as a bridge between domain experts and the public. Terminologists ensure conceptual accuracy, consistency, and clarity across definitions, adapting terminology to be both scientifically valid and accessible to non-specialist audiences. Their expertise is essential in developing terminology that meets the dual goals of precision and public understanding. Building on insights from Freitag and Pfeffer (2013), who emphasize the value of citizen perspectives, this report argues for a participatory, expert-guided approach to terminology validation. By integrating terminologists into the co-design of definitions and incorporating feedback from non-expert users, the process supports more transparent, inclusive, and effective communication in citizen science projects across Europe.