EMA has published Medical terms simplifier – a list of plain-language descriptions of medical terms commonly used in information about medicines.
The focus is on side effects and other terms used in medicines information and assessments of medicines. A list could be consulted for e.g. when PL is being updated and patient friendly term is needed.
https://www.ema.europa.eu/en/documents/other/ema-medical-terms-simplifier_en.pdf