The term "active service" refers to a person or thing that is currently in use, operation, or being employed for its intended purpose. In military contexts, it means serving on active duty and participating in combat operations or other missions. Soldiers, sailors, airmen, and marines are said to be on "active service" when they are deployed overseas or within their own country, carrying out their assigned duties and responsibilities. The term can also refer to equipment that is currently being used by military personnel, such as vehicles, weapons, and other gear. In summary, the phrase "active service" signifies a state of readiness, engagement, and involvement in current operations or activities.