The integration of terminologies is still a challenging problem in medical informatics research and software applications, due to the high number of heterogeneous terminologies. In this paper, we present a generic API (Application Programming Interface) for a multi-terminology multilingual terminology service, and PyMedTermino, its open-source implementation in Python with 5 terminological resources (ICD10, SNOMED CT, MedDRA, CDF, VCM iconic language) and the UMLS compendium. This service has been designed for research and educational purpose. It offers various advanced functionalities rarely present in terminology services.