Definition of "EMS"

(business) electronics manufacturing service: a type of OEM (original equipment manufacturer) service.  examples

(US, medicine) emergency medical service: an organization, often part of a local government whose purpose is to provide emergency medical care to the public.  quotations  examples

(business) express mail service: a type of international express mail services.  examples

(dated, computing) Expanded Memory Specification  examples

environmental management system  examples